Modular garment for a wearable medical device

ABSTRACT

An ergonomic and unobtrusive cardiac monitoring and treatment device for continuous wear includes a band, ECG sensing electrodes and treatment electrodes configured to deliver an electrotherapy, one or more sensor ports for receiving one or more physiological sensors, and a controller for analyzing an ECG signal of a patient and causing a delivery of electro therapy. The band is configured to be worn about a thoracic region and has a vertical span of between about 1 to about 15 centimeters. The band is configured to be immobilized relative to a skin surface of the thoracic region of the patient by exerting one or more compression forces against the thoracic region. The device can include at least two separate wearable portions comprising a band portion including ECG sensing electrodes and/or other physiological sensors, and a second wearable portion optionally separable from the band portion, the second wearable portion including treatment electrodes.

BACKGROUND

The present disclosure is directed to wearable medical devices, forexample wearable monitoring devices and wearable monitoring andtreatment devices.

A wide variety of electronic and mechanical devices monitor and treatmedical conditions. In some examples, depending on the underlyingmedical condition being monitored or treated, medical devices such ascardiac monitors or defibrillators may be surgically implanted orexternally connected to a patient. In some cases, physicians may usemedical devices alone or in combination with drug therapies to treatconditions such as cardiac arrhythmias.

One of the most deadly cardiac arrhythmias is ventricular fibrillation,which occurs when normal, regular electrical impulses are replaced byirregular and rapid impulses, causing the heart muscle to stop normalcontractions. Normal blood flow ceases, and organ damage or death canresult in minutes if normal heart contractions are not restored. Becausethe victim has no perceptible warning of the impending fibrillation,death often occurs before medical assistance can arrive. Other cardiacarrhythmias can include excessively slow heart rates known asbradycardia or excessively fast heart rates known as tachycardia.Cardiac arrest can occur when the heart experiences various arrhythmiasthat result in the heart providing insufficient levels of blood flow tothe brain and other vital organs for the support of life. Sucharrhythmias include, for example, ventricular fibrillation, ventriculartachycardia, pulseless electrical activity (PEA), and asystole (heartstops all electrical activity).

Cardiac arrest and other cardiac health ailments are a major cause ofdeath worldwide. Various resuscitation efforts aim to maintain thebody's circulatory and respiratory systems during cardiac arrest in anattempt to save the life of the patient. Implementing theseresuscitation efforts quickly improves the patient's chances ofsurvival. Implantable cardioverter/defibrillators (ICDs) or externaldefibrillators (such as manual defibrillators or automated externaldefibrillators (AEDs)) have significantly improved success rates fortreating these otherwise life-threatening conditions. Such devicesoperate by applying corrective electrical pulses directly to thepatient's heart. Ventricular fibrillation or ventricular tachycardia canbe treated by an implanted or external defibrillator, for example, byproviding a therapeutic shock to the heart in an attempt to restorenormal rhythm. To treat conditions such as bradycardia, an implanted orexternal pacing device can provide pacing stimuli to the patient's heartuntil intrinsic cardiac electrical activity returns.

Example external cardiac monitoring and/or treatment devices includecardiac monitors, the ZOLL LifeVest® wearable cardioverter defibrillatoravailable from ZOLL Medical Corporation, and the AED Plus also availablefrom ZOLL Medical Corporation.

External pacemakers, defibrillators and other medical monitors designedfor ambulatory and/or long-term use have further improved the ability totimely detect and treat life-threatening conditions. For example,certain medical devices operate by continuously monitoring the patient'sheart through one or more sensing electrodes for treatable arrhythmiasand, when such is detected, the device applies corrective electricalpulses directly to the heart through two or more treatment electrodes.

Example cardiac monitoring and treatment devices can include a vest orgarment worn by the patient and a monitoring and treatment monitorcoupled to electrodes disposed in the vest or garment. These devices areprescribed for continuous wear by the patient for long periods of time.As such, the vest or garment must be optimized for patient comfort andefficacious device operation. Further, patients are generallydiscouraged from discontinuing use of the device without consulting withtheir caregivers. Accordingly, the devices are to be worn in compliancewith caregiver instructions to ensure maximum protection from adverseevents.

SUMMARY

In one example, an ergonomic and unobtrusive cardiac monitoring andtreatment device for continuous wear includes a band configured to beworn about a thoracic region of a patient within a T1 thoracic vertebraregion and a T12 thoracic vertebra region. The band has a vertical spanof between 1 to 15 centimeters along at least 50 percent of a length ofthe band, the band being configured to be immobilized relative to a skinsurface of the thoracic region of the patient by exerting one or morecompression forces against the thoracic region. The band includes aplurality of electrodes and associated circuitry disposed about theband. The plurality of electrodes and associated circuitry disposedabout the band includes at least one pair of ECG sensing electrodesdisposed about the band and an ECG acquisition circuit in communicationwith the at least one pair of ECG sensing electrodes. The at least onepair of ECG sensing electrodes can be configured to sense an ECG signalof the patient, and the ECG acquisition circuit is configured to provideECG information for the patient based on the sensed ECG signal. Theplurality of electrodes and associated circuitry disposed about the bandincludes at least one pair of treatment electrodes and a treatmentdelivery circuit being in communication with the at least one pair oftreatment electrodes. The at least one pair of treatment electrodes areconfigured to deliver an electrotherapy to the patient, a first one ofthe at least one pair of treatment electrodes being configured to belocated within an anterior area of the thoracic region and a second oneof the at least one pair of treatment electrodes being configured to belocated within a posterior area of the thoracic region of the patient,and the treatment delivery circuit is configured to cause delivery ofthe electrotherapy to the patient. The band includes one or more sensorports for receiving one or more physiological sensors separate from theat least one pair of ECG sensing electrodes.

The device includes a controller including an ingress-protected housing,and a processor disposed within the ingress-protected housing. Theprocessor is configured to analyze the ECG information of the patientfrom the ECG acquisition circuit and detect one or more treatablearrhythmias based on the ECG information, and cause the treatmentdelivery circuit to deliver the electrotherapy to the patient ondetecting the one or more treatable arrhythmias.

Implementations of the device may include one or more of the followingfeatures.

In one example, the band is configured to be worn about the thoracicregion with in a T5 thoracic vertebra region and a T11 thoracic vertebraregion. The band can be configured to be worn about the thoracic regionwith in a T8 thoracic vertebra region and a T10 thoracic vertebraregion.

In an example, the band can be configured to exert the one or morecompression forces in a range from 0.025 psi to 0.75 psi. The band canbe configured to exert the one or more compression forces in a rangefrom 0.05 psi to 0.70 psi to the thoracic region. The band can beconfigured to exert the one or more compression forces in a range from0.075 to 0.675 psi to the thoracic region. The band can be configured toexert the one or more compression forces in a range from 0.1 to 0.65 psito the thoracic region.

In examples, the band has a vertical span in a range of 2 to about 12centimeters along at least 50 percent of a length of the band. The bandcan have a vertical span in a range of 3 to about 8 centimeters along atleast 50 percent of a length of the band.

In an example, the device includes a conductive wiring configured tocommunicatively couple the controller to the plurality of electrodes andassociated circuitry disposed about the band.

In examples, the ingress-protected housing includes at least oneingress-protected connector port configured to receive at least oneconnector of the conductive wiring. In implementations, the at least oneingress-protected connector port has an IP67 rating.

In implementations, the band is continuously worn over an extendedperiod of time.

In examples, the one or more sensor ports are in communication with theprocessor via a conductive wiring disposed about the band.

In examples, the band is sized to fit about the thoracic region of thepatient by matching the length of the band to one or morecircumferential measurements of the thoracic region during an initialfitting. In implementations, band proportions and dimensions are derivedfrom patient-specific thoracic 3D scan dimensions such that the band issized to fit proportions, dimensions, and shape of the thoracic region.

In examples, the compression portion includes an adjustable fastener forsecuring the band about the thoracic region of the patient within therange of compression forces. In some examples, the compression portionincludes an unbroken loop of a stretchable fabric defining the band. Inimplementations, the band is configured to stretch over the shoulders orhips of the patient and contract when positioned about the thoracicregion. The stretchable fabric can include at least one of elasticpolyurethane fiber neoprene, spandex, nylon-spandex, nylon-LYCRA, ROICA,LINEL, INVIYA, ELASPAN, ACEPORA, and ESPA. In implementations, thecompression portion includes an elasticized thread disposed in the band.In implementations, the compression portion includes an elasticizedpanel disposed in the band, and the elasticized panel is a portion ofthe band spanning less than a total length of the band. Inimplementations, the compression portion includes an adjustable tensionelement disposed in the band.

In implementations, the band comprises a breathable skin-facing layerhaving an MVTR of between about 600 g/m2/day and about 1,400 g/m2/day.In implementations, the skin-facing layer includes at least one of acompression padding, a silicone tread, and one or more textured surfacecontours.

In examples, the device includes an adhesive configured to secure theband to the thoracic region of the patient. In implementations, theadhesive is configured to be removable.

In examples, the band includes at least one visible indicator of bandtension disposed on a posterior surface of the band.

In some examples, the band includes at least one of an anteriorappendage and a posterior appendage, and at least one of the pluralityof electrodes is disposed on the at least one of the anterior appendageand the posterior appendage. In implementations, each of the at leastone of the anterior appendage and the posterior appendage is a flapextending vertically along the thoracic region from a circumferentialtop or bottom edge of the band. In implementations, the at least one ofthe anterior appendage and the posterior appendage cumulatively occupy50 percent or less of the length of the band. In implementations, anaverage vertical rise from a bottom edge of the band to a top edge ofeach of the at least one of the anterior appendage and the posteriorappendage is greater than the average vertical rise of the band.

In one example, a cardia includes a controller including at least oneprocessor, a first wearable portion, and a second wearable portionseparate from the first wearable portion. In examples, the firstwearable portion includes an elongated strap configured to encircle athoracic region of a patient. The elongated strap is configured to beimmobilized relative to a skin surface of the thoracic region of thepatient by exerting one or more compression forces against the thoracicregion. The first wearable portion includes a plurality of ECG sensingelectrodes disposed about the elongated strap. The plurality of ECGsensing electrodes are configured to sense an ECG signal of the patient.The first wearable portion includes one or more receiving portsconfigured to receive one or more additional components including atleast one of a treatment electrode and an additional sensor, and theplurality of conductive wires configured to couple the plurality of ECGsensing electrodes and the one or more receiving ports with thecontroller.

The second wearable portion is configured to be worn over at least oneshoulder of the patient. The second wearable portion includes a wearablesubstrate, and one or more treatment electrodes disposed on the wearablesubstrate. The one or more treatment electrodes include a correspondingconductive surface configured to contact an anterior area and aposterior area of the thoracic region of the patient. The secondwearable portion includes at least one conductive wire configured toreleasably connect the one or more treatment electrodes to thecontroller.

Implementations of the system may include one or more of the followingfeatures.

In examples, the elongated strap has a vertical span in a range of 1 toabout 15 centimeters along at least 50 percent of a length of theelongated strap. The elongated strap can have a vertical span in a rangeof 2 to about 12 centimeters along at least 50 percent of a length ofthe elongated strap. The elongated strap can have a vertical span in arange of 3 to about 8 centimeters along at least 50 percent of a lengthof the elongated strap.

In examples, the second wearable portion is configured to be worn for acumulative duration less than or equal to a duration of wear of thefirst wearable portion.

In some examples, the second wearable portion has a compression forcerelatively lower than the one or more compression forces of theelongated strap.

In examples the system includes an ECG acquisition circuit incommunication with the plurality of ECG sensing electrodes and the atleast one processor and configured to provide ECG information for thepatient based on the sensed ECG signal. In implementations, the at leastone processor is configured to provide a notification to the patient towear the second wearable portion upon detecting the impending cardiacevent. In implementations, the notification includes an instruction toconnect the at least one conductive wire of the second wearable portionto the controller. In implementations, the at least one processorprovides, via the output device, an indication of successful connectionof the at least one conductive wire of the second wearable portion tothe controller.

In examples, the at least one processor is configured to initiatedelivery of a therapeutic shock via the one or more treatmentelectrodes.

In examples, the elongated strap exerts the one or more compressionforces such that the elongated strap is immobile relative to a skinsurface of the thoracic region. In implementations, the elongated strapis configured to exert the one or more compression forces in a rangefrom 0.025 psi to 0.75 psi. In implementations, the elongated strap isconfigured to exert the one or more compression forces in a range from0.05 to 0.70 psi to the thoracic region. In implementations, theelongated strap is configured to exert the one or more compressionforces in a range from 0.075 to 0.675 psi to the thoracic region. Inimplementations, the elongated strap is configured to exert the one ormore compression forces in a range from 0.1 to 0.65 psi to the thoracicregion.

In examples, the elongated strap is sized to fit about the thoracicregion. The elongated strap can be sized to fit by matching a length ofthe elongated strap to one or more circumferential measurements of thethoracic region during an initial patient fitting. Elongated strapdimensions can be derived from a 3D scan of the thoracic region suchthat the elongated strap is sized to fit proportions, dimensions, andshape of the thoracic region. In implementations, the elongated strap is3D printed to at least one of body proportions, body shape, bodyposture, and linear surface measurements of the thoracic region of thepatient. In implementations, at least a portion of the elongated strapis 3D-printed to conform the sash to one or more portions of thethoracic region.

In examples, at least one fastener is disposed on a first end of theelongated strap for adjoining a second end of the elongated strap insecured attachment about the thoracic region of the patient. Inimplementations, the elongated strap includes an adjustable latchingmechanism configured to secure the elongated strap about the thoracicregion of the patient.

In examples, the second wearable portion can be at least one of a shirt,a vest, a bandeau, a pinnie, a butterfly harness, a yoke, and a dickie.The first and second wearable portions are configured to be worn beneatha clothing of the patient.

In examples, the first wearable portion includes an appendagemechanically attached to the elongated strap. The appendage isconfigured to be continuously worn about the thoracic region of thepatient. In implementations, the appendage includes at least oneadditional ECG sensing electrode in communication with the plurality ofconductive wires of the elongated strap, the at least one additional ECGsensing electrode being configured to sense the ECG signal of thepatient in conjunction with the plurality of ECG sensing electrodes ofthe elongated strap. The appendage comprises at least one treatmentelectrode in communication with the at least one processor, the at leastone treatment electrode configured to provide a therapeutic shock. Inimplementations, the at least one treatment electrode is in wiredcommunication with the plurality of conductive wires of the elongatedstrap. In implementations, the appendage is a flap. In implementations,the appendage is an over-the-shoulder sash. In implementations, theappendage is a pair of over-the shoulder sashes crossing over theanterior area of the thoracic region. In implementations, the appendageis configured to be affixed to the elongated strap. In implementations,the appendage is monolithically formed with the elongated strap.

In examples, the elongated strap comprises a breathable skin-facinglayer having an MVTR of between about 600 g/m2/day and about 1,400g/m2/day.

In one example, an ergonomic and unobtrusive cardiac monitoring andtreatment device for continuous wear includes a sash, a plurality ofelectrodes and associated circuitry disposed about the sash, and acontroller. The sash is configured to be worn over a shoulder of apatient, encircling a thoracic region of the patient, extending fromover a first shoulder of the patient across an anterior area of thethoracic region to an opposite lateral side of the thoracic region undera second shoulder of the patient adjacent to the axilla and furtherextending across a posterior area of the thoracic region from under thesecond shoulder to over the first shoulder. The plurality of electrodesand associated circuitry disposed about the sash include at least onepair of ECG sensing electrodes disposed about the sash, an ECGacquisition circuit in communication with the at least one pair of ECGsensing electrodes, and at least one pair of treatment electrodescoupled to a treatment delivery circuit.

The at least one pair of ECG sensing electrodes disposed about the sashare configured to sense an ECG signal of the patient, and the ECGacquisition circuit in communication with the at least one pair of ECGsensing electrodes is configured to provide ECG information of thepatient based on the sensed ECG signal. The at least one pair oftreatment electrodes coupled to the treatment delivery circuit isconfigured to deliver an electrotherapy to the patient. A first one ofthe at least one pair of treatment electrodes is configured to belocated within the anterior area of the thoracic region and a second oneof the at least one pair of treatment electrodes is configured to belocated within the posterior area of the thoracic region of the patient.The treatment delivery circuit in communication with the at least onepair of treatment electrodes is configured to cause delivery of theelectrotherapy to the patient.

The controller includes an ingress-protected housing, and a processordisposed within the ingress-protected housing. The processor isconfigured to analyze the ECG information of the patient from the ECGacquisition circuit and detect one or more treatable arrhythmias basedon the ECG information, and cause the treatment delivery circuit todeliver the electrotherapy to the patient on detecting the one or moretreatable arrhythmias.

Implementations of the device may include one or more of the followingfeatures.

In examples, the sash is sized to fit the thoracic region. Inimplementations, sized to fit comprises determining dimensions of thethoracic region in an initial fitting. In implementations, sashproportions and dimensions are derived from a 3D scan of the thoracicregion such that the sash is sized to fit proportions, dimensions, andshape of the thoracic region.

In examples, the sash is 3D printed to at least one of body proportions,body shape, body posture, and linear surface measurements of thethoracic region of the patient. In implementations, at least a portionof the sash is 3D-printed to conform the sash to one or more portions ofthe thoracic region.

In examples, the sash is configured to be immobilized relative to a skinsurface of the thoracic region of the patient by exerting one or morecompression forces against the thoracic region. In implementations, thesash is configured to exert the one or more compression forces in arange from 0.025 psi to 0.75 psi. In implementations, the sash isconfigured to exert the one or more compression forces in a range from0.05 psi to 0.70 psi to the thoracic region. In implementations, thesash is configured to exert the one or more compression forces in arange from 0.075 to 0.675 psi to the thoracic region. Inimplementations, the sash is configured to exert the one or morecompression forces in a range from 0.1 to 0.65 psi to the thoracicregion.

In implementations, the device includes an adhesive configured to securethe sash to the thoracic region of the patient such that the sash isimmobile relative to a skin surface of the thoracic region. The adhesivecan be replaceable.

In implementations, the device includes a plurality of conductive wiresconfigured to communicatively couple the controller to the plurality ofelectrodes and associated circuitry disposed about the sash.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an embodiment of a patient-worn medical device.

FIG. 2A depicts an embodiment of a patient-worn cardiac monitoring andtreatment device comprising band.

FIG. 2B depicts a schematic of the band of FIG. 2A.

FIG. 3 depicts an embodiment of a patient-worn cardiac monitoring andtreatment device relative to a posterior depiction of a patient'sskeletal anatomy.

FIG. 4 depicts an embodiment of a patient-worn cardiac monitoring andtreatment device relative to an anterior depiction of a patient'sskeletal anatomy.

FIG. 5 depicts an embodiment of a patient-worn cardiac monitoring andtreatment device comprising band and cross-shoulder appendages.

FIG. 6A depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion and a secondwearable portion.

FIG. 6B depicts a schematic of the first wearable portion of FIG. 6A.

FIG. 7 depicts a schematic diagram of an embodiment of a controller of apatient-worn cardiac monitoring and treatment system.

FIG. 8A depicts an embodiment a method of computing a sudden cardiacarrhythmia risk score.

FIG. 8B depicts an embodiment of a timeline associated with a durationof wear of the patient-worn cardiac monitoring and treatment system.

FIG. 9A depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising an overthe shoulder appendage and a second wearable portion comprising a vest.

FIG. 9B depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising two overthe shoulder appendages and a second wearable portion comprising a vest.

FIG. 10A depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising suspenders.

FIG. 10B depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising suspenders.

FIG. 11A depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising a holster.

FIG. 11B depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising a holster.

FIG. 12A depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising a butterfly harness.

FIG. 12B depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a second wearable portion comprising a butterfly harness.

FIG. 13 depicts an embodiment of a patient-worn cardiac monitoring andtreatment system comprising a first wearable portion comprising a strapand a yoke.

FIG. 14 depicts an embodiment of a patient-worn cardiac monitoring andtreatment device comprising a cross-body sash.

FIG. 15 is a schematic of an example method of using a patient-worncardiac monitoring and treatment device.

FIG. 16. depicts a schematic diagram of an embodiment of electricalcomponents of a patient-worn cardiac monitoring and treatment device.

DETAILED DESCRIPTION

This disclosure relates to various improvements in one or more features,implementations, and design configurations of wearable cardiacmonitoring and/or treatment devices over conventional devices. Patientsprescribed with such life critical devices need to be able to wear themcontinuously through daily activities to ensure near constant protectionagainst life-threatening cardiac arrhythmia conditions over extendedperiods of time. Accordingly, the devices herein provide improvedergonomics and physiological benefits that promote better voluntarycompliance with device use guidelines than conventional devices. One setof examples herein is based on a wearable defibrillator band or strapthat is worn unobtrusively and comfortably under the patient'sundergarments. Another set of examples feature at least two separatewearables portions that can also be worn unobtrusively and comfortably.A first wearable portion includes ECG sensing electrodes and/or otherphysiological sensors. Additionally, a second wearable portion isoptionally separable from the first wearable portion and includestreatment electrodes.

Briefly, the wearable defibrillator band is worn about a thoracic regionof a patient, in particular, within a T1 thoracic vertebra region and aT12 thoracic vertebra region. The band includes certain light weightelements such as electrocardiogram (ECG) sensors and treatmentelectrodes in close proximity or in direct contact with the patient'sskin, as well as associated circuitry necessary for the device toacquire and process the ECG signals. To secure the sensors andelectrodes in close proximity or in direct contact with the patient'sskin, the band includes a compression portion that immobilizes the bandrelative to the patient's skin as the patient moves and goes about adaily routine. The circuitry in the band is electrically coupled to acontroller housed within an ingress-protected housing, which includesheavier energy storage elements such as capacitors and batteries.

Because no portion of the band traverses the patient's limbs orshoulders, the patient is free to move, bend, twist and lift his or herarms and/or shoulders without imparting torque on the device 100. Thisimmobilizes the band relative to the patient's skin and prevents oreliminates signal noise associated with sensors shifting against theskin when compared to wearable devices that run over a patient'sshoulder or arm. The size and position of the band also provides adiscreet and comfortable device covering only a relatively small portionof the surface area of a patient's entire thoracic region andaccommodating a plurality of body types. A relatively small portion canbe for example, 25%, or less (e.g. 20%, 15%, 10%, 5% or less than 5%) ofthe surface area of the thoracic region 105. Covering only a relativelysmall portion of the thoracic region further improves comfort andencourages patient compliance because the patient will feel little or nodiscomfort and may forget the band is being worn.

These features as well as others described herein thus provide certainadvantages over conventional wearable defibrillators at least in termsof comfort, patient compliance, and minimizing false arrhythmia alerts.

Turning to the two separable wearable portions embodiment, disclosedherein is a first wearable portion that includes an elongated strapconfigured to encircle a thoracic region of a patient and exert a radialcompression force to secure the strap on the patient. The strap includesthe ECG sensing electrodes as well as one or more receiving portions toreceive additional components including treatment electrodes andadditional sensors (e.g., non-ECG physiological sensors or motionsensors). The second wearable portion is configured to be worn over atleast one shoulder of the patient and includes a wearable substrate onwhich one or more treatment electrodes is disposed. In examples, thesecond wearable portion includes treatment electrodes, and the ECGsensing electrodes in the first wearable portion as well as thetreatment electrodes in the second wearable portion are togetherelectrically coupled to a controller housed within an ingress-protectedhousing including the capacitors and batteries. In certainimplementations, the second wearable portion is implemented to fullysupport the device capacitors and batteries, e.g., wherein suchcapacitors and batteries are evenly weight distributed within the secondwearable portion. The second wearable portion can be worn optionally andfor a shorter duration than the first wearable portion such that apatient can avoid wearing treatment portions of the device duringuneventful monitoring periods. The second wearable portion can be worn,for example, only when a patient is deemed at potential risk for asudden cardiac event occurring within some period of time (e.g. 1 day, 1week, 2 weeks). The treatment electrodes of the second wearable portionare configured to couple to wiring of the first wearable portion and/ora receiving port disposed on the housing that is in electricalcommunication with a processor of the controller.

Wearable medical devices as disclosed herein include cardiac monitoringand/or treatment devices that monitor electrocardiogram (ECG) signalsand, in certain examples, other physiological signals of patientswearing such devices. For example, the medical device can be used as acardiac monitor in certain cardiac monitoring applications, includingheart failure and arrhythmia monitoring applications. In someimplementations, the medical device can be configured to monitor otherphysiological parameters as an alternative or in addition to ECG signalsand/or metrics. In addition to or instead of cardiac monitoring, suchdevices may also monitor respiratory parameters (e.g., to monitorcongestion, lung fluid status, apnea, etc.), patient activity (e.g.,posture, gait, sleep conditions, etc.) and other physiologicalconditions. In some implementations, the medical device can beconfigured to include one or more treatment components interoperablewith and, in embodiments, selectively connected to one or moremonitoring components.

In some implementations, a patient-worn cardiac monitoring and treatmentdevice detects one or more treatable arrhythmias based on physiologicalsignals from a patient. The treatable arrhythmias include those that maybe treated by defibrillation pulses, such as ventricular fibrillation(VF) and shockable ventricular tachycardia (VT), or by pacing pulses,such as bradycardia, tachycardia, and asystole. A wearable medicaldevice as disclosed herein monitors a patient's physiologicalconditions, e.g., cardiac signals, respiratory parameters, and patientactivity, and delivers potentially life-saving treatment to the patient.The medical device can include a plurality of sensing electrodes thatare disposed at various locations on the patient's body and configuredto monitor the cardiac signals of the patient such as electrocardiogram(ECG) signals. In some implementations, the device can also beconfigured to allow a patient to report his/her symptoms including oneor more skipped beat(s), shortness of breath, light headedness, racingheart, fatigue, fainting, and chest discomfort. The device determines anappropriate treatment for the patient based on the detected cardiacsignals and/or other physiological parameters prior to delivering atherapy to the patient. The device can then cause one or moretherapeutic shocks, for example, defibrillating and/or pacing shocks, tobe delivered to the body of the patient. The wearable medical deviceincludes a plurality of treatment electrodes disposed on the patient'sbody and configured to deliver the therapeutic shocks.

As described in U.S. Pat. No. 8,983,597, titled “MEDICAL MONITORING ANDTREATMENT DEVICE WITH EXTERNAL PACING,” issued on Mar. 17, 2015(hereinafter the “'597 Patent”), which is hereby incorporated herein byreference in its entirety, an example patient worn cardiac monitoringand treatment device can be, for example, an ambulatory medical devicethat is capable of and designed for moving with the patient as thepatient goes about his or her daily routine. For example, as shown inFIG. 1, the ambulatory medical device 10 can be a wearable cardioverterdefibrillator (WCD) and can include one or more of the following: agarment 11, one or more physiological sensors 12 (e.g., ECG electrodes,heart rate sensors, vibrational sensors, and/or other physiologicalsensors), one or more treatment electrodes 14 a and 14 b (collectivelyreferred to herein as treatment electrodes 14), a medical devicecontroller 20, a connection pod 30, a patient interface pod 40, a belt50 about the patient's torso to support one or more components, or anycombination of these. In some examples, at least some of the componentsof the medical device 10 can be configured to be affixed to the garment11 (or in some examples, permanently integrated into the garment 11),which can be worn about the patient's torso 5.

The medical device controller 20 can be operatively coupled to thephysiological sensors 12 which can be affixed to the garment 11, e.g.,assembled into the garment 11 or removably attached to the garment 11,e.g., using hook and loop fasteners. In some implementations, thephysiological sensors 12 can be permanently integrated into the garment11. The medical device controller 20 can be operatively coupled to thetreatment electrodes 14. For example, the treatment electrodes 14 canalso be assembled into the garment 11, or, in some implementations, thetreatment electrodes 14 can be permanently integrated into the garment11.

In embodiments according to this disclosure, such as that of FIGS. 2A-6Band 9A-14, one or more portions of the garment 11 of the device 10 ofFIG. 1 can be eliminated or distributed about separately donned wearableportions. In embodiments, permanently or temporarily eliminating one ormore portions of the garment 11 results in leaving a device configuredwith relatively less surface area. Such a wearable device can includeone or more of, for example, a belt, a harness, a bandeau, a sash, avest, a yoke, and/or a pinnie. In implementations, the device can befitted to the body as a lightweight stretchable support garment.

Systems and techniques are disclosed herein to improve ergonomics of theone or more wearable portions of such a wearable medical device.Patients are encouraged to comply with the device use guidelines,including wearing the device at all times including while showering orsleeping. To improve patient compliance with these guidelines, thedevices described herein include one or more wearable portions that arelightweight, comfortable, and discreet so that they may be worn underthe patient's clothing. In some implementations described herein, thedevices include various features that promote comfort and efficacy whilecontinuing to protect the patient from adverse cardiac events. Inimplementations, the devices are fitted to nest with the contours of apatient's body, including, for example, the shoulder-neck region and/orthe thoracic region. In implementations described herein, the devicesinclude one or more wearable portions configured to be worn continuouslyand/or selectively, each of the one or more wearable portions configuredto support one or more monitoring and/or treatment components. Based onan analysis of monitored signals and output from a predictive algorithmconfigured to determine the likelihood of a cardiac event, the devicecan instruct the patient on when to add additional monitoring and/ortreatment components to the one or more wearable portions, and/or whento add an additional one or more wearable portions including one or moremonitoring and/or treatment components. In modular implementations ofthe wearable medical device including two or more interoperable wearableportions, each portion can include one or more of the aforementionedmonitoring and treatment components.

In an example scenario, a patient may be prescribed the wearable medicaldevice following a medical appointment. For example, the such a wearablemonitoring and/or treatment device can be prescribed for patients thatmeet certain criteria. Examples may include or more of the followingcriteria: (1) Primary prevention (ejection fraction (EF) ≤35% andMyocardial Infarction (MI), nonischemic cardiomyopathy (NICM), or otherdilated cardiomyopathy (DCM)), including after recent MI (e.g.,typically worn for about 40 days ICD waiting period), before and aftercoronary artery bypass grafting (CABG) or percutaneous transluminalcoronary angioplasty (PTCA) (e.g., typically worn for about 90 day ICDwaiting period), while listed for cardiac transplant, when recentlydiagnosed with nonischemic cardiomyopathy (e.g., typically worn forabout 3 to 9 month ICD waiting period), when diagnosed with New YorkHeart Association (NYHA) class IV heart failure, and when diagnosed withterminal disease with life expectancy of less than 1 year; (2) ICDindications when patient condition delays or prohibits ICD implantation;and (3) ICD explanation.

Wearing the device protects the patient from life-threateningarrhythmias, while also enabling the collection of diagnosticinformation for additional, potentially more invasive procedures. Theexample devices described herein are prescribed to be worn continuouslyand typically for a prescribed duration of time. For example, theprescribed duration can be a duration for which a patient is instructedby a caregiver to wear the device in compliance with device useinstructions. The prescribed duration may be for a short period of timeuntil a follow up medical appointment (e.g., 1 hour to about 24 hours, 1day to about 14 days, or 14 days to about one month), or a longer periodof time (e.g., 1 month to about 3 months) during which diagnosticsinformation about the patient is being collected even as the patient isbeing protected against cardiac arrhythmias. The prescribed use can beuninterrupted until a physician or other caregiver provides a specificprescription to the patient to stop using the wearable medical device.For example, the wearable medical device can be prescribed for use by apatient for a period of at least one week. In an example, the wearablemedical device can be prescribed for use by a patient for a period of atleast 30 days. In an example, the wearable medical device can beprescribed for use by a patient for a period of at least one month. Inan example, the wearable medical device can be prescribed for use by apatient for a period of at least two months. In an example, the wearablemedical device can be prescribed for use by a patient for a period of atleast three months. In an example, the wearable medical device can beprescribed for use by a patient for a period of at least six months. Inan example, the wearable medical device can be prescribed for use by apatient for an extended period of at least one year.

Because these devices require continuous operation and wear by patientsto which they are prescribed, advantages of the implementations hereininclude use of comfortable, non-irritating, biocompatible constructionmaterials, and features designed to enhance patient compliance. Suchcompliance-inducing design features include, for example, deviceergonomics and inconspicuous appearance when worn under output garments,among others.

In some implementations, the device includes monitoring and treatmentcomponents disposed in or on a cross-body, shoulder-to-hip sash or in oron a monolithic band configured to encircle a thoracic region. Thedevice can be held in compression against the thoracic region so as tominimize or eliminate sensor signal noise and other artifacts. Inimplementations, the device includes a first wearable portion configuredto be worn about the thoracic region for monitoring the patient and oneor more ports disposed on the first wearable portion and coupled to adata bus. The one or more ports are configured to receive additionalmonitoring and/or treatment components for selectively addingfunctionality to the device. In implementations, the device includes afirst wearable portion configured to be worn about the thoracic regionfor monitoring the patient, and a second, later-added portion. Thesecond wearable portion can be configured to connect to the monitoringcomponents and provide therapeutic treatment to the patient upondetection of a treatable condition. Splitting the components over one ormore garments ensures that larger, heavier, and/or infrequently usedcomponents, such as defibrillation treatment electrodes, are worn by thepatient only when necessary. This distribution of the components of thedevice over two or more wearable portions lessens patient discomfortthroughout a prescribed duration of wear and encourages patientcompliance with caregiver instructions.

The devices described here can be prescribed to be worn continuously andfor long durations of time, often over the course of several weeks ormonths. Substantially continuous or nearly continuous use as describedherein may nonetheless qualify as continuous use. In someimplementations, the patient may remove the wearable medical device fora short portion of the day (e.g., for half an hour while bathing).

At least a monitoring portion of the wearable medical device can becontinuously or nearly continuously worn by the patient. Continuous usecan include continuously monitoring the patient while the patient iswearing the device for cardiac-related information (e.g.,electrocardiogram (ECG) information, including arrhythmia information,cardiac vibrations, etc.) and/or non-cardiac information (e.g., bloodoxygen, the patient's temperature, glucose levels, tissue fluid levels,and/or pulmonary vibrations). For example, the wearable medical devicecan carry out its continuous monitoring and/or recording in periodic oraperiodic time intervals or times (e.g., every few minutes, hours, oncea day, once a week, or other interval set by a technician or prescribedby a caregiver). Alternatively or additionally, the monitoring and/orrecording during intervals or times can be triggered by a user action oranother event.

As noted previously, the wearable medical device can be configured tomonitor other physiologic parameters of the patient in addition tocardiac related parameters. For example, the wearable medical device canbe configured to monitor, for example, pulmonary vibrations (e.g., usingmicrophones and/or accelerometers), breath vibrations, sleep relatedparameters (e.g., snoring, sleep apnea), and tissue fluids (e.g., usingradio-frequency transmitters and sensors), among others.

FIGS. 2A-B illustrate an example cardiac monitoring and treatment device100 that is external, ambulatory, and wearable by a patient. The device100 is an external or non-invasive medical device, which, for example,is located external to the body of the patient and configured to providetranscutaneous therapy to the body. The device 100 is an ambulatorymedical device, which, for example, is capable of and designed formoving with the patient as the patient goes about his or her dailyroutine.

The device 100 can include a band 110 configured to be worn about athoracic region 105 of a patient within a T1 thoracic vertebra regionand a T12 thoracic vertebra region, as depicted in FIGS. 3 and 4. Forexample, the device 100 can include a band 110 configured to be wornwithin a T5 thoracic vertebra region and a T11 thoracic vertebra region.For example, the device 100 can include a band 110 configured to be wornwithin a T8 thoracic vertebra region and a T10 thoracic vertebra region.As shown in FIG. 2B, the band 110 can have a vertical span V1, ofbetween about 1 to about 15 centimeters along at least 50 percent of alength L1 of the band 110. For example, in implementations, the verticalspan V1 is between 2 to 12 centimeters along at least 50 percent of thelength L1. For example, in implementations, the vertical span V1 isbetween 3 to 8 centimeters along at least 50 percent of the length L1.In implementations, the band 110 includes a compression portion disposedin the band 110. In implementations, the band 110 exerts compressionforces against the skin of the patient by one or more of manufacturingall or a portion of the band 110 from a compression fabric, proving oneor more tensioning mechanisms in and/or on the band 110, and providing acinching closure mechanism for securing and compressing the band 110about the thoracic region 105. The compression portion is configured toimmobilize the band 110 relative to a skin surface of the thoracicregion 105 of the patient by exerting one or more compression forcesagainst the thoracic region. In implementations, the band is configuredto exert the one or more compression forces in a range from 0.025 to0.75 psi to the thoracic region 105. For example, the one or morecompression forces can be in a range from 0.05 psi to 0.70 psi, 0.075psi to 0.675 psi., or 0.1 to 0.65 psi.

Compression forces of the medical device can be determined, for example,using one or more pressure sensors distributed about the band 110 anddisposed between the band 110 and the thoracic region 105. The one ormore pressure sensors can be, for example, one or more force sensitiveresistors, one or more Polydimethylsiloxane (PDMS)-based flexibleresistive strain sensors, one or more capacitive pressure sensors,and/or a tactile array of sensors such as those sold by PPS of LosAngeles, Calif. The one or more pressure sensors can be, for example,ultra-thin (e.g. 0.1 mm or less), flexible pressure sensors. Inimplementations, the ultra-thin, flexible pressure sensors can beconfigured to provide pressure mapping using a system for example suchas a TEKSCAN measurement and mapping system, including the I-SCAN systemby Tekscan, Inc. of South Boston, Mass. In other implementations, thecompression forces of the medical device can be modeled using afabric-based analytical module employing tensile data. In otherimplementations, the compression forces can be measured using amechanical measurement system such as the Hohenstein Measurement System,such as the HOSYCAN, manufactured by Hohenstein, Bönnigheim, Germany.

In implementations, compliance with one or more compression forces ofembodiments described herein can be determined in accordance with thefollowing test fixtures and conditions. The device 100 can be mounted ona mannequin such as for example, one manufactured by Alvanon. In anexample, the mannequin has thoracic circumferential dimensions rangingfrom 66 cm to 142 cm. In some examples, the garment may be fit onpatients such that a garment extends to approximately 1″ below theunderbust for fitting the patient. One or more of the exemplary sensorspreviously described can be inserted between the mounted device 100 andthe mannequin (or patient) at a plurality of arbitrary locations, forexample, 5 locations spaced apart along the circumference of the band110. In some examples, the locations may be chosen to be at bothanterior and posterior positions about the thoracic region of themannequin (or patient). Compression forces can then be measured andindividually compared to the one or more compression ranges describedherein. Alternatively, or in addition, the one or more measuredcompression forces can be averaged and the average force compared to theone or more compression ranges described herein. The test can beconducted under temperature and humidity conditions of 0-60 degreesCelsius and 10-90% humidity. Further, the test can be conducted in a wetenvironment (e.g., the device mounted on the mannequin or patient isexposed to water) to simulate bathing and/or showering conditions.

As shown in FIG. 2A, the device 100 includes a plurality of electrodesand associated circuitry disposed about the band 110. The plurality ofelectrodes can include at least one pair of sensing electrodes 112disposed about the band 110 and configured to be in electrical contactwith the patient. The sensing electrodes 112 can be configured to detectone or more cardiac signals such as ECG signals. Example ECG sensingelectrodes 112 include a metal electrode with an oxide coating such astantalum pentoxide electrodes, as described in, for example, U.S. Pat.No. 6,253,099 entitled “Cardiac Monitoring Electrode Apparatus andMethod,” the content of which is incorporated herein by reference. Thedevice 100 can include an ECG acquisition circuit in communication withthe at least one pair of ECG sensing electrodes 112 and configured toprovide ECG information for the patient based on the sensed ECG signal.In implementations, the at least one pair of ECG sensing electrodes 112can include a driven ground electrode, or right leg drive electrode,configured to ground the patient and reduce noise in the sensed ECGsignal.

The plurality of electrodes can include at least one pair of treatmentelectrodes 114 a and 114 b (collectively referred to herein as treatmentelectrodes 114) and an associated treatment delivery circuit configuredto cause delivery of the electrotherapy to the patient. The at least onepair of treatment electrodes 114 can be configured to deliver anelectrotherapy to the patient. For example, one or more of the at leastone pair of treatment electrodes 114 can be configured to deliver one ormore therapeutic defibrillating shocks to the body (e.g., the thoracicregion 105) of the patient when the medical device 100 determines thatsuch treatment is warranted based on the signals detected by the sensingelectrodes 112 and processed by the medical device controller 120.Example treatment electrodes 114 include, for example, conductive metalelectrodes such as stainless steel electrodes that include, in certainimplementations, one or more conductive gel deployment devicesconfigured to deliver conductive gel to the metal electrode prior todelivery of a therapeutic shock. In implementations, a first one of theat least one pair of treatment electrodes 114 a is configured to belocated within an anterior area of the thoracic region 105 and a secondone of the at least one pair of treatment electrodes 114 b is configuredto be located within a posterior area of the thoracic region 105 of thepatient. In some implementations, the anterior area can include a sidearea of the thoracic region.

In some examples, at least some of the plurality of electrodes andassociated circuitry of the device 100 can be configured to beselectively affixed or attached to the band 110 which can be worn aboutthe patient's thoracic region 105. In some examples, at least some ofthe plurality of electrodes and associated circuitry of the device 100can be configured to be permanently secured into the band 110. Inimplementations, the plurality of electrodes are manufactured asintegral components of the band 110. For example, the at least one pairof treatment electrodes 114 and/or the at least one pair of ECG sensingelectrodes can be formed of the warp and weft of a fabric forming atleast a layer of the band 110. In implementations, the treatmentelectrode 114 and the ECG sensing electrodes 112 are formed fromconductive fibers that are interwoven with non-conductive fibers of thefabric. Additional implementations of sensing electrode arrangements andtreatment electrode arrangements on a patient-worn medical device areprovided herein in subsequent sections.

In implementations, the device 100 can include one or more sensor ports115 a-c (collectively referred to as 115) for receiving one or morephysiological sensors separate from the at least one pair of ECG sensingelectrodes. The one or more physiological sensors can be, for example,sensors for detecting one or more of pulmonary vibrations (e.g., usingmicrophones and/or accelerometers), breath vibrations, sleep relatedparameters (e.g., snoring, sleep apnea), and tissue fluids (e.g., usingradio-frequency transmitters and sensors). The additional sensor can be,for example, one or more physiological sensors including a pressuresensor for sensing compression forces of the garment, SpO2 sensors,blood pressure sensors, bioimpedence sensors, humidity sensors,temperature sensors, and photoplethysmography sensors. In some examples,the sensor ports 115 a-c can also be configured to receive one or moremotion and/or position sensors. For example, such motion sensors caninclude accelerometers for monitoring the movement of the patient'storso in x-, y- and z-axes to determine a movement of the patient, gait,and/or whether the patient is upright, standing, sitting, lying down,and/or elevated in bed with pillows. In certain implementations, one ormore gyroscopes may also be provided to monitor an orientation of thepatient's torso in space to provide information on, e.g., whether thepatient is lying face down or face up, or a direction in which thepatient is facing.

In implementations, the device 100 includes a controller 120 includingan ingress-protected housing, and a processor disposed within theingress-protected housing. In implementations, as shown in FIG. 7, thecontroller 120 can include a processor 218, a therapy delivery circuit1130 including a polarity switching component such as an H-bridge 1128,a data storage 1207, a network interface 1206, a user interface 1208, atleast one battery 1140, a sensor interface 1202 that includes, forexample, an ECG data acquisition and conditioning circuit, an alarmmanager 1214, one or more capacitors 1135, and a Sudden CardiacArrhythmia (SCA) Risk Analysis Assessor 219.

The processor 218 is configured to analyze the ECG information of thepatient from the ECG acquisition circuit and detect one or moretreatable arrhythmias based on the ECG information and cause thetreatment delivery circuit to deliver the electrotherapy to the patienton detecting the one or more treatable arrhythmias. The medical devicecontroller 120 can be operatively coupled to the sensing electrodes 112,which can be affixed to the band 110. In embodiments, the sensingelectrodes 112 are assembled into the band 110 or removably attached tothe garment, using, for example, hook and loop fasteners, thermoformpress fit receptacles, snaps, and magnets, among other restraints. Insome implementations, as described previously, the sensing electrodes112 can be a permanent portion of the band 110. The medical devicecontroller 120 also can be operatively coupled to the treatmentelectrodes 114. For example, the treatment electrodes 114 can also beassembled into the band 110, or, as described previously, in someimplementations, the treatment electrodes 114 can be a permanent portionof the band 110. Optionally, the device 100 can includes a connectionpod 130 in wired connection with one or more of the plurality ofelectrodes and associated circuitry. In some examples, the connectionpod 130 includes at least one of the ECG acquisition circuit and asignal processor configured to amplify, filter, and digitize the cardiacsignals prior to transmitting the cardiac signals to the medical devicecontroller 120. In implementations, the device 100 can include at leastone ECG sensing electrode 112 configured to be coupled to the upperportion of the thoracic region 105, above the band 110, the at least oneECG sensing electrode 112 being in wired communication with the ECGacquisition circuitry and at least one of the connection pod and thecontroller 120.

In implementations, the device includes a conductive wiring 140configured to communicatively couple the controller to the plurality ofelectrodes and associated circuitry disposed about the band. Inimplementations, the conductive wiring 140 can be woven into the warpand weft of the fabric. In implementations, the conductive wiring 140can be integrated into the fabric, disposed between layers of the band110. In implementations, the conductive wiring 140 can include one ormore conductive threads integrated into the fabric of the band 110. Inexamples, the one or more conductive threads can be integrated in azigzag or other doubled back pattern so as to straighten as the band 110stretches. The zigzag or doubled-back pattern therefore accommodates forstretching and patient movement while keeping the one or more conductivethreads from contacting the skin of the patient. Integrating theconductive wiring 140 into the band 110 reduces and/or eliminatessnagging the wire or thread on an external object. In other examples,the conductive thread can be routed on an exterior surface of the band110 so as to avoid contacting the skin of the patient and thereforeavoid irritation associated with such potential contact. Inimplementations, the conductive wiring 140 includes two or moreconductive wires bundled within an insulating outer sheath. Inimplementations, the conductive wiring 140 can be routed along the band110 and held securely to the band 110 by one or more loops of fabric,closable retention tabs, eyelets and/or other retainers so that theconductive wiring 140 does not snag on or bulge beneath a patient'sclothing worn over the band 110.

In implementations, the conductive wiring 140 extends between thecontroller 120 and plurality of electrodes and associated circuitry andthe one or more sensor ports 115. The one or more sensor ports 115 caninclude thereon a connector for receiving a complimentary mating portionof one or more additional sensors selectively disposed on the band 110.The connector of the one or more sensor ports 115 can be in wiredcommunication with the conductive wiring 140 such that upon receiving asensor therein, a sensor port 115 functions as a conduit forcommunicating information between the sensor and the processor 218 ofthe controller 120.

The ingress-protected housing of the controller 120 protects thecomponents thereunder (e.g., the processor 218, the therapy deliverycircuit 1130 including a polarity switching component such as anH-bridge 1128, a data storage 1207, a network interface 1206, a userinterface 1208, at least one battery 1140, the sensor interface 1202,the alarm manager 1214, the one or more capacitors 1135, and the SuddenCardiac Arrhythmia (SCA) Risk Analysis Assessor 219) from externalenvironmental impact, for example damage associated with solid particleingress, dust ingress, and/or moisture, water vapor or liquid ingress.In implementations, for example, the ingress-protected housing can be atwo-piece housing having two interlocking shell portions configured tobe mated in a sealed press fit. For example, a compressible grommet,o-ring, or silicon seal can be inserted between and/or about the matingsurfaces such that ingress into the interlocked shall portions isprevented. Similarly, any additional openings can be similarly sealed toprevent ingress, such as any openings comprising user input buttons orelectronics ports for mating with wired components. In some examples,ports for receiving wire connectors therein can be sealed to the housingof the controller 120 with an epoxy to prevent ingress.

Preventing such ingress protects the electronic components of the device100 from short-circuiting or corrosion of moisture-sensitiveelectronics, for example, when a patient wears the device whileshowering. In implementations, the ingress-protected housing of thecontroller 120 includes at least one ingress-protected connector port121 configured to receive at least one connector 141 of the conductivewiring 140. The at least one ingress-protected connector port can havean IP67 rating such that the device can be connected to the controller120 and operable when a patient is showering or bathing, for example.

Example implementations of water-resistant housings of the controller120 protect against liquid ingress in accordance with one or morescenarios as set forth in Table 1:

TABLE 1 Protection Effective Against (e.g. shall not impact normalAgainst operation of the medical device as described herein) Drippingwater Falling drops of dripping water on the medical device housing,e.g., water dripping on the housing at a rate 1 mm per minute for aperiod of around 10 minutes. Spraying water Spray of water falling onthe medical device housing at any angle up to 60 degrees from vertical.Splashing of Water splashing against the housing from any direction.water Water jets Water projected by a nozzle (e.g., a nozzle of 6.3 mmdiameter) against the housing from any direction Powerful water Waterprojected in powerful jets (e.g., a nozzle jets of 12.5 mm diameterspraying water at a pressure of 100 kPa at a distance of 3 m) againstthe housing from any direction Immersion, up to The housing is immersedin water at a depth of up to 1 meter. 1 m depth Immersion, 1 m Thehousing is immersed in water at a depth of 1 meter or more. or moredepth Powerful high The housing is sprayed with a high pressure (e.g.8-10 MPa), high temperature temperature (e.g. 80 degrees Celsius) sprayat close range. water jets

In some implementations, the ingress-protected housing on the controller120 is water-resistant and has a predetermined ingress protection ratingcomplying with one or more of the rating levels set forth in IECstandard 60529. The liquid Ingress Protection rating can be one or moreof any level (e.g., levels 3 to 9) in which rating compliance tests arespecified in the standard. For example, to have a liquid ingressprotection rating level of six, the ingress-protected housing of thecontroller 120 shall protect against ingress of water provided by apowerful water jet. The powerful water jet test requires that thehousing of the controller 120 is sprayed from all practicable directionswith a stream of water from a test nozzle having a 12.5 mm diameter.Water sprays for 1 minute per square meter for a minimum of threeminutes at a volume of 100 liters per minute (+/−5 percent) so that acore of the stream of water is a circle of approximately 120 mmm indiameter at a distance of 2.5 meters from the nozzle. For example, tohave a rating level of 7, ingress of water shall not be possible whenthe housing of the controller 120 is completely immersed in water at adepth between 0.15 m and 1 m so that the lowest point of the housing ofthe controller 120 with a height less than 850 mm is located 1000 mmbelow the surface of the water and the highest point of a housing of thecontroller 120 with a height less than 850 mm is located 150 mm belowthe surface of the water. The controller 120 is immersed for a duration30 minutes, and the water temperature does not differ from that of thehousing of the controller 120 by more than 5K. Table 2 provides therating levels and tests for liquid Ingress Protection in accordance withIEC standard 60529:

TABLE 2 Rating Degree of Protection Test conditions, see Level BriefDescription Definition IEC 60529 section 0 Non-protected — — 1 Protectedagainst Vertically falling 14.2.1 vertically falling drops shall have nowater drops harmful effects 2 Protected against Vertically falling14.2.2 vertically falling drops shall have no water drops when harmfuleffects when housing tilted up the housing is tilted to 15 degrees atany angle up to 15 degrees on either side of the vertical 3 Protectedagainst Water sprayed at an 14.2.3, including, spraying water angle upto 60 degrees for example, on either side of the spraying water onvertical shall have the housing at 60 no harmful effects degrees fromvertical at a water flow rate of 10 liters/min for at least 5 minutes 4Protected against Water splashed against 14.2.4, including, splashingwater the housing from any for example, direction shall have sprayingwater on no harmful effects the housing at 180 degrees from vertical ata water flow rate of 10 liters/min for at least 5 minutes 5 Protectedagainst Water projected in 14.2.5, including, for water jets jetsagainst example, spraying the housing from water from a 6.3 mm anydirection shall diameter nozzle have no harmful effects at a distance of2.5-3 m from the housing at a water flow rate of 12.5 liters/min for atleast 3 minutes 6 Protected against Water projected in 14.2.6,including, powerful waterjets powerful jets against for example,spraying the housing from any water from a 12.5 mm direction shall havediameter nozzle at a no harmful effects distance of 2.5-3 m from thehousing at a water flow rate of 100 liters/min for at least 3 minutes 7Protected against Ingress of water in 14.2.7, including, for the effectsof quantities causing example, immersion temporary immersion harmfuleffects shall for 30 min in a water in water not be possible when tanksuch that the the housing is bottom of the housing temporarily immersedis 1 m below the in water under surface of the water standardizedconditions and the top of the of pressure and time housing is 0.15 mbelow the surface of the water 8 Protected against Ingress of water in14.2.8, including, for the effects of quantities causing example,immersion in continuous immersion harmful effects shall a water tanksuch that in water not be possible when the bottom of the the housing ishousing is greater than continuously immersed 1 m below the surface inwater under of the water and the conditions which top of the housing isshall be agreed greater than 0.15 m between manufacturer below thesurface of and user but which are the water more severe than for numeral7 9 Protected against Water projected at 14.2.9, including, for highpressure and high pressure and example, spraying temperature water hightemperature water on the housing jets against the housing from allpractical from any direction directions from a fan shall not have jetnozzle at a distance harmful effects of 175 +/− 25 mm from the housingand spraying water at a flow rate of 15 liters/min for at least 3 min

For example, the housing of the controller 120 can be constructed to bewater-resistant and tested for such in accordance with the IEC 60529standard for Ingress Protection. For instance, the controller 120 of thedevice 100 may be configured to have a rating of level 7, protectingagainst immersion in water, up to one meter for thirty minutes. Thisenables a patient to wear the device 100 in the bathtub or shower foruninterrupted, continuous use. In implementations, the controller 120 ofthe device 100 may be multiple coded, including two or more levels. Forexample, the controller 120 of the device 100 can maintain a liquidIngress Protection level of 7, protecting against temporary immersion,and a liquid Ingress Protection level of 5, protecting against waterjets.

As described previously, the housing of the controller 120 shields oneor more of the contents within the controller from environmental impact.These contents can include one or more of the treatment deliverycircuit, an ECG acquisition and conditioning circuit, the processor, atleast one capacitor, and at least one power source (e.g., a battery).The controller 120 covers and/or surrounds the hardware componentstherein, protecting them from wear and tear and protecting the patientfrom contacting high voltage components. The controller 120 protects thecomponents from liquid ingress while the patient is showering, forexample. In examples, the housing of the controller 120 can comprise orconsist of at least one of neoprene, thermoformed plastic, or injectionmolded rubber or plastic, such as silicone or other biocompatiblesynthetic rubber.

Additionally, the band 110 can be water vapor-permeable, andsubstantially liquid-impermeable or waterproof. The band 110 maycomprise or consist of an elastic polyurethane fiber that providesstretch and recovery. For example, the band 110 may comprise or consistof at least one of neoprene, spandex, nylon-spandex, nylon-LYCRA, ROICA,LINEL, INVIYA, ELASPAN, ACEPORA, and ESPA. In implementations, a portionof the band 110 comprises a water resistant and/or waterproof fabriccovering and/or encapsulating electronic components including, forexample, the sensing electrodes 112, the treatment electrodes 114, andthe conductive wiring 140, and a portion of the band comprises a waterpermeable, breathable fabric having a relatively higher moisture vaportransmission rate that the water resistant and/or waterproof portions.In examples, the band 110 can comprise or consist of a fabric having abiocompatible surface treatment rendering the fabric water resistantand/or waterproof. For example, the fabric can be enhanced by dipping ina bath of fluorocarbon, such as Teflon or fluorinated-decyl polyhedraloligomeric silsesquioxane (F-POSS). Additionally or alternatively, theband 110 can comprise or consist of a fabric including anti-bacterialand/or anti-microbial yarns. For example, these yarns can include a basematerial of at least one of nylon, polytetrafluoroethylene, andpolyester. These yarns can be for example, one or more of anantibacterial silver coated yarn, antibacterial DRAYLON yarn, DRYTEXANTIBACTERIAL yarn, NILIT BREEZE and NILIT BODYFRESH. Inimplementations, the outer surface of the band 110 can comprise one ormore patches of an electrostatically dissipative material such as aconductor-filled or conductive plastic in order to prevent static clingof a patient's clothing. Alternatively, in embodiments, the band 110comprises a static dissipative coating such as LICRON CRYSTAL ESD SafeCoating (TECHSPRAY, Kennesaw, Ga.), a clear electrostatic dissipativeurethane coating.

Returning to FIGS. 2A-B, the band 110 can be sized to fit about thethoracic region 105 of the patient by matching the length L1 of the band110 to one or more circumferential measurements of the thoracic region105 during an initial fitting. For example, in an initial fitting, acaregiver, physician or patient service representative (PSR) can measurethe circumference of the thoracic region 105 of the patient at one ormore locations disposed about the thoracic region 105 between about theT1 thoracic region and the T12 thoracic region, and select a band 110having a length L1 within a range of 2-25% longer than the largestmeasured circumference. Having the band 110 be longer than the largestmeasured circumference of the thoracic region 105 can provide thepatient with a comfort advantage of loosening and tightening the band110 to accommodate fluctuations in body mass throughout the prescribedduration of wear. In embodiments of the device 100 having a fastenerconfigured to secure the band 110 about the thoracic region 105, thepatient can loosen or reposition the band around one or more positionsalong the thoracic region 105 between about the T1 thoracic region andT12 thoracic region.

Additionally or alternatively, the band 110 can have proportions anddimensions derived from patient-specific thoracic 3D scan dimensions.From a 3-dimensional scan of the thoracic region 105 of the patient, aband can be sized to fit proportions, dimensions, and shape of thethoracic region 105. In implementations, for example, various body sizemeasurements and/or contoured mappings may be obtained from the patient,and one or more portions of the band 110 can be formed of a plastic orpolymer to have contours accommodating one or more portions of thethoracic region in a nested fit. For example one or more portions of theband may be 3D printed from, for example, any suitable thermoplastic(e.g., ABS plastic) or any elastomeric and/or flexible 3D printablematerial. For example the band 110 may include at least two curved rigidor semi-rigid portions 109 a, 109 b for engaging the patient's sides,under the arms. The at least two curved portions add rigid structurethat assists with preventing the band 110 from shifting or rotatingabout the thoracic region. This stability provides consistency of sensorsignal readings and prevents noise associated with sensor movement.

Stability of the device is also provided by the at least one compressionportion. The compressive forces of the band 110 prevent movement of theband 110 relative to the skin surface of the thoracic region 105 andreduce or eliminate noise artifacts associated with sensors movingrelative to the surface of the skin of the thoracic region 105. In oneimplementation, the band 110 includes joinable ends 145 a, 145 b, andthe compression portion comprises an adjustable fastener 147 forsecuring the band about the thoracic region 105 of the patient withinthe range of compression forces. The range of compression forces securesthe band 110 from movement without the patient developing soreness orcompression ulcers during the continuous period of wear. Inimplementations, the fastener can include a ratchet, a belt buckle, hookand loop fasters, snaps, buttons, eyelets, and any other mechanism forclosing the band 110.

In implementations, the band 110 comprises at least one visibleindicator 149 of band tension disposed on a surface of the band 110. Forexample, the visible indicator 149 can be a color changing indicatorincorporated in the band 110 indicating whether the band 110 is tooloose, overtightened, or compressed within the range of compressiveforces. As the band 110 stretches, the material forming the visibleindicator 149, for example, can change color between blue, indicatingover-tensioning or under-tensioning, and yellow or green, indicatingproper tensioning for simultaneously enabling sensor readings andpatient comfort. In one implementation, the visible indicator 149 cancomprise one or more stretchable, multilayer smart fibers disposed in oron the band 110. The one or more smart fibers change color from red, toorange, to yellow, to green and to blue as strain on the fiberincreases. Providing a visible indication directly on the band 110enables a patient to adjust or reapply the band 110 so that the at leastone pair of ECG sensing electrodes 112 and at least one pair oftreatment electrodes 114 are properly positioned and immobilized on thethoracic region 105 and so that the band isn't overtightened andapplying compressive forces in the thoracic region 105 to a level ofpatient discomfort. In other implementations, the band can include amechanical strain gauge in or on the band 110. The mechanical straingauge can be communicatively coupled to the conductive wiring 140 suchthat the controller 120 provides an audible and/or visible indication ofwhether the band is over-tightened, too loose, or within the range ofcompression forces enabling effective use and wear comfort.

In implementations, the band comprises an unbroken loop and thecompression portion comprises a stretchable fabric defining the band110. The band 110 can be configured to stretch over the shoulders orhips of the patient and contract when positioned about the thoracicregion 105. In implementations, the stretchable fabric comprises atleast one of nylon, LYCRA, spandex, and neoprene. During an initialfitting, the physician, caregiver, or PSR can select a band 110 sized tofit the patient. For example, the physician, caregiver, or PSR canmeasure a circumference about one or more locations on the thoracicregion 105. The physician, caregiver, or PSR can select a band having acircumference within about 75% to about 95% of the measurement of theone or more locations about the thoracic region 105. In someimplementations, the compression portion comprises an elasticized threaddisposed in the band 110. The compression portion can comprise anelasticized panel disposed in the band, the elasticized panel comprisinga portion of the band 110 spanning less than a total length of the band110. For example, the band 110 can include one or more mechanicallyjoined sections forming a continuous length or unbroken loop. The one ofthe one or more sections can comprise a stretchable fabric and/orelasticized thread interspersed with non-stretchable or relatively lessstretchable portions. In other embodiments, the band 110 can include acompression portion comprising an adjustable tension element, such asone or more cables disposed in the band 110 and configured to be pulledtaught and held in tension by one or more pull stops. In allembodiments, the band 110 can include one or more visible or mechanicaltension indicators configured to provide a notification of the band 110exerting compression forces against the thoracic region 105 in a rangefrom about 0.025 psi to 0.75 psi.

As described herein, the band 110 is immobilized by compression forcesand configured to minimize shifting as the patient moves and goes abouta daily routine. Because no portion of the band 110 traverses thepatient's limbs or shoulders, the patient is free to move, bend, twistand lift his or her arms and/or shoulders without imparting torque onthe device 100. This immobilizes the band 110 relative to the skinsurface of the thoracic region and prevents or eliminates signal noiseassociated with sensors shifting against the skin when compared towearable devices that run over a patient's shoulder or arm. The size andposition of the band 110 also provides a discreet and comfortable device100 covering only a relatively small portion of the surface area of theentire thoracic region 105 and accommodating a plurality of body types.A relatively small portion can be for example, 25%, or less (e.g. 20%,15%, 10%, 5% or less than 5%) of the surface area of the thoracic region105. Covering only a relatively small portion of the thoracic region 105further improves comfort and encourages patient compliance because thepatient will feel little or no discomfort and may forget the device 100is being worn. In implementations, the band comprises a breathable,skin-facing layer including at least one of a compression padding, asilicone tread, and one or more textured surface contours. Thebreathable material and compression padding enable patient comfortthroughout the duration of wear and the silicon tread and/or one or moresurface contours assist with immobilizing the band relative to the skinsurface of the thoracic region.

Implementations of the device 100 in accordance with the presentdisclosure may exhibit a moisture vapor transmission rate (MVTR) of, forexample, between about 600 g/m2/day and about 1,400 g/m2/day when wornby a subject in an environment at room temperature (e.g., about 25° C.)and at a relative humidity of, for example, about 70%. Inimplementations, the device 100 has a water vapor permeability of 100g/m²/24 hours, as measured by such vapor transmission standards of ASTME-96-80 (Version E96/E96M-13), using either the “in contact with watervapor” (“dry”) or “in contact with liquid” (“wet”) methods. Such testmethods are described in in U.S. Pat. No. 9,867,976, titled “LONG-TERMWEAR ELECTRODE,” issued on Jan. 16, 2018 (hereinafter the “'976Patent”), the disclosure of which is incorporated by reference herein inits entirety. In implementations, the band 110 comprises one or moremoisture wicking fabrics for assisting with moving moisture away fromthe skin of the thoracic region 105 and improving patient comfortthroughout the prescribed duration of wear.

In implementations, the device includes an adhesive configured toimmobilize the band 110 relative to the thoracic region of the patient.In implementations, the adhesive is configured to be a removable and/orreplaceable adhesive patch for preventing the band 110 from shifting,rotating, or slipping relative to the skin of the thoracic region. Inimplementations, once the patient is wearing the band 110 and hasadjusted the band in implementations comprising an adjustment and/ortightening mechanism, the patient can insert on or more adhesive patchesbetween the band 110 and the skin. In implementations, the patient canswap out one or more adhesive patches with one or more new adhesivepatches in the same or a different location between the band 110 and theskin of the thoracic region 105. For example, the patient may swap outthe one or more adhesive patches on a daily schedule or may use theadhesive patches selectively during periods of high activity, such aswhile exercising. The adhesives can include biocompatible adhesives,such as pressure-sensitive adhesives having tack, adhesion, and cohesionproperties suitable for use with a medical device applied to skin forshort term and long-term durations. These pressure sensitive adhesivescan include polymers such as acrylics, rubbers, silicones, andpolyurethanes having a high initial tack for adhering to skin. Thesepressure sensitive adhesives also maintain adhesion during showering orwhile a patient is perspiring. The adhesives also enable removal withoutleaving behind uncomfortable residue. For example, such an adhesive canbe a rubber blended with a tackifier.

In implementations, the adhesive comprises one or more water vaporpermeable adhesive patches. The adhesive can be a conductive patchdisposed between the plurality of electrodes and the skin of thoracicregion 105, in some implementations. For example, as described in the'976 Patent, a water-vapor permeable conductive adhesive patch can be,for example, the flexible, water vapor-permeable, conductive adhesivematerial can comprise a material selected from the group consisting ofan electro-spun polyurethane adhesive, a polymerized microemulsionpressure sensitive adhesive, an organic conductive polymer, an organicsemi-conductive conductive polymer, an organic conductive compound and asemi-conductive conductive compound, and combinations thereof. In anexample, a thickness of the flexible, water vapor-permeable, conductiveadhesive material can be between 0.25 and 100 mils. In another example,the water vapor-permeable, conductive adhesive material can compriseconductive particles. In implementations, the conductive particles maybe microscopic or nano-scale particles or fibers of materials, includingbut not limited to, one or more of carbon black, silver, nickel,graphene, graphite, carbon nanotubes, and/or other conductivebiocompatible metals such as aluminum, copper, gold, and/or platinum.

The device 100 herein includes low skin-irritation fabrics and/oradhesives. In embodiments, the device 100 may be worn continuously by apatient for a long-term duration (e.g., duration of at least one week,at least 30 days, at least one month, at least two months, at leastthree months, at least six months, and at least one year) without thepatient experiencing significant skin irritation. For example, a measureof skin irritation can be based on skin irritation grading of one ormore as set forth in Table C.1 of Annex C of American National StandardANSI/AAMI/ISO 10993-10:2010, reproduced here in the entirety:

TABLE 3 Table C. 1 - Human Skin irritation test, grading scaleDescription of response Grading No reaction 0 Weakly positive reaction(usually characterized 1 by mild erythema and/or dryness across most ofthe treatment site) Moderately positive reaction (usually distinct 2erythema or dryness, possibly spreading beyond the treatment site)Strongly positive reaction (strong and often 3 spreading erythema withedema and/or eschar formation)

The skin irritation grading of one represents a weakly positive reactionusually characterized by mild erythema and/or dryness across most of thetreatment site. In one implementation, a measure of skin irritation canbe determined by testing on human subjects in accordance with the methodset forth in American National Standard ANSI/AAMI/ISO 10993-10:2010, byapplying sample patches of the adhesive and/or fabric to treatment sitesfor up to four hours, and, in the absence of skin irritation,subsequently applying sample patches to treatment sites for up to 24hours. The treatment sites are examined for signs of skin irritation,and the responses are scored immediately after patch removal and at timeintervals of (1±0.1) h to (2±1) h, (24±2) h, (48±2) h and (72±2) h afterpatch removal. In another implementation, a patient may wear the device100 as instructed for a duration of (24±2) hours, and if the patient'sskin shows no reaction at the end of this duration, the device 100 israted as a skin irritation grading of zero.

Treatment is caused to be provided by the treatment delivery circuit incommunication with the at least one pair of treatment electrodes 114. Inimplementations, as shown in FIGS. 2A and 2B, the band 110 furthercomprises at least one of an anterior appendage 150 and a posteriorappendage 155, and at least one of the plurality of electrodes isdisposed on the at least one of the anterior appendage and the posteriorappendage. In implementations, one treatment electrode 114 a of the atleast one pair of treatment electrodes 114 is disposed on the anteriorappendage 150 and one treatment electrode 114 b of the at least one pairof treatment electrodes 114 is disposed on the posterior appendage 155.In implementations, each of the at least one of the anterior appendageand the posterior appendage is a flap extending vertically along thethoracic region from a circumferential top edge 160 or a circumferentialbottom edge 165 of the band 110. In implementations, the anteriorappendage and the posterior appendage cumulatively occupy 50 percent orless of the length of the band 110 so as to minimize the surface area ofthe thoracic region 105 covered by the device 100 which providing aneffective placement of the at least one pair of treatment electrodes114. By positioning the at least one pair of treatment electrodes 114 oneither side of the patient's heart, the device 100 can deliver effectivetreatment along a vector through the heart, restoring a normal rhythmupon detection of a cardiac arrhythmia requiring treatment. As depictedin FIGS. 2A-B, the anterior and posterior appendages 150, 155 rise froma top circumferential edge 160 of the band 110. In such implementations,an average vertical rise V2, V3 from a bottom edge 165 of the band 110to a top edge 170, 175 of each of the at least one of the anteriorappendage 150 and the posterior appendage 155 is greater than theaverage vertical rise V1 of the band.

In implementations, at least one of the anterior appendage 150 and theposterior appendage 155 includes disposed thereon at least one ECGsensing electrode 112. In implementations, such as that of FIG. 5, thedevice can include one or more appendages 111 a, 111 b mechanicallyattached to the band 110, the one or more appendages 111 a, 111 b,configured to be continuously worn about the thoracic region 105 of thepatient. In addition to supporting one more additional ECG sensingelectrodes 112 thereon, the one or more appendages 111 a, 111 b areconfigured to receive one or more selectively added treatment electrodes114, shown in dashed line to indicate their being added to the device100 optionally. In implementations, the device 100 can be configured tomonitoring a patient's ECG signal, analyze the signal, predict a futureevent occurring based on the analysis, and provide an instruction topatient or caregiver to add the optional treatment electrodes to the oneor more appendages 111 a, 111 b and the band 110.

In other implementations, such as that of FIG. 6A, a cardiac monitoringand treatment system 200 includes a first wearable portion 205 and asecond, separately worn portion 215 including one or more treatmentelectrodes 214 a, 214 b (collectively referred to as 214) disposed onthe second wearable portion 215. The treatment electrodes 214 aredisposed in the second wearable portion 215 such that a treatment vectorformed between the treatment electrodes 214 is aligned through thepatient's heart when the second wearable portion 215 is worn.

In implementations, a cardiac monitoring and treatment system caninclude a controller 220 comprising at least one processor, a firstwearable portion 205, and a second wearable portion 215. Inimplementations, as shown in FIG. 7, the controller 220 can include theat least one processor 218, a therapy delivery circuit 1130 including apolarity switching component such as an H-bridge 1128, a data storage1207, a network interface 1206, a user interface 1208, at least onebattery 1140, a sensor interface 1202 that includes, for example, an ECGdata acquisition and conditioning circuit, an alarm manager 1214, one ormore capacitors 1135, and a Sudden Cardiac Arrhythmia (SCA) RiskAnalysis Assessor 219.

In implementations, the first wearable portion 205 includes an elongatedstrap 210, similar to the band 110 of FIGS. 2A-B, configured to encirclea thoracic region 105 of a patient. The elongated strap 210 isconfigured to be immobilized relative to a skin surface of the thoracicregion 105 of the patient by exerting one or more compression forcesagainst the thoracic region. For example, the compression force can bein a range from 0.025 psi to 0.75 psi, 0.05 psi to 0.70 psi, 0.075 psito 0.675 psi., or 0.1 to about 0.65 psi. In implementations, the strap210 exerts compression forces against the skin of the patient by one ormore of manufacturing all or a portion of the strap 210 from acompression fabric, providing one or more tensioning mechanisms inand/or on the strap 210, and proving a cinching closure mechanism forsecuring and compressing the strap 210 about the thoracic region 105.Compression forces of the medical device can be determined, for example,using one or more pressure sensors and systems as described above withregard to the band 110 of FIG. 2A. The first wearable portion 205includes a plurality of ECG sensing electrodes 212 disposed about theelongated strap 210. The plurality of ECG sensing electrodes isconfigured to sense an ECG signal of the patient. The plurality of ECGsensing electrodes 212 can be disposed about the elongated strap 210 andconfigured to be in electrical contact with the patient. Inimplementations, the plurality of ECG sensing electrodes can include adriven ground electrode, or right leg drive electrode, configured toground the patient and reduce noise in the sensed ECG signal.

In embodiments, the plurality of ECG sensing electrodes 212 areconfigured to be assembled into the elongated strap 210 or removablyattached to the elongated strap, using, for example, hook and loopfasteners, thermoform press fit receptacles, snaps, and magnets, amongother restraints. An example ECG sensing electrode 212 includes a metalelectrode with an oxide coating such as tantalum pentoxide electrodes,as described in, for example, U.S. Pat. No. 6,253,099 entitled “CardiacMonitoring Electrode Apparatus and Method,” the content of which isincorporated herein by reference. In some implementations, as describedpreviously, the plurality of ECG sensing electrodes 212 can be apermanent portion of the elongated strap 210. For example, the pluralityof ECG sensing electrodes 212 can be formed of the warp and weft of afabric forming at least a layer of the elongated strap 210. Inimplementations, the plurality of ECG sensing electrodes 212 are formedfrom conductive fibers that are interwoven with non-conductive fibers ofthe fabric. In some implementations, the plurality of ECG sensingelectrodes 212 are metallic plates (e.g. stainless steel) or substratesthat are formed as permanent portions of the elongated strap 210. Ametallic plate or substrate can be adhered to the elongated strap 210,for example, by a polyurethane adhesive or a polymer dispersion adhesivesuch as a polyvinyl acetate (PVAc) based adhesive, or other suchadhesive. In examples, the plurality of ECG sensing electrodes 212 are aplurality of dry ECG sensing electrodes. In examples, plurality of ECGsensing electrodes 212 are flexible, dry surface electrodes such as, forexample, conductive polymer-coated nano-particle loaded polysiloxaneelectrodes mounted to the elongated strap 210. In some examples, theplurality of ECG sensing electrodes 212 are flexible, dry surfaceelectrodes such as, for example silver coated conductive polymer foamsoft electrodes mounted to the elongated strap 210. In examples, theplurality of ECG sensing electrodes 212 are screen printed onto theelongated strap 210 with a metallic ink, such as a silver-based ink. Inimplementations, each of the plurality of ECG sensing electrodes 212 hasa conductive surface adapted for placement adjacent the patient's skin.

In implementations, the first wearable portion 205 includes one or morereceiving ports 213 configured to receive one or more additionalcomponents including at least one of a treatment electrode 214 and anadditional sensor. The additional sensor can be, for example, one ormore physiological sensors for detecting one or more of pulmonaryvibrations (e.g., using microphones and/or accelerometers), breathvibrations, sleep related parameters (e.g., snoring, sleep apnea), andtissue fluids (e.g., using radio-frequency transmitters and sensors).The additional sensor can be, for example, one or more physiologicalsensors including a pressure sensor for sensing compression forces ofthe garment, SpO2 sensors, blood pressure sensors, bioimpedence sensors,humidity sensors, temperature sensors, and photoplethysmography sensors.In implementations, the one or more receiving ports 213 enable the oneor more additional components to be assembled into the elongated strap210 or removably attached to the elongated strap 210, using, forexample, hook and loop fasteners, thermoform press fit receptacles,snaps, and magnets, among other restraints and/or mating features. Insome examples, the ports 213 can also be configured to receive one ormore motion and/or position sensors. For example, such motion sensorscan include accelerometers for monitoring the movement of the patient'storso in x-, y- and z-axes to determine a movement of the patient, gait,and/or whether the patient is upright, standing, sitting, lying down,and/or elevated in bed with pillows. In certain implementations, one ormore gyroscopes may also be provided to monitor an orientation of thepatient's torso in space to provide information on, e.g., whether thepatient is lying face down or face up, or a direction in which thepatient is facing.

In implementations, the first wearable portion 205 includes a pluralityof conductive wires 240 configured to couple the plurality of ECGsensing electrodes 212 and the one or more receiving ports 213 with thecontroller 220. In implementations, the plurality of conductive wires240 extends between the controller 220 and plurality of ECG sensingelectrodes 212 and the one or more receiving ports 213. The one or morereceiving ports 213 can include thereon a connector for receiving acomplimentary mating portion of one or more additional sensorsselectively disposed on the elongated strap 210. The connector of theone or more ports 213 can be in wired communication with the pluralityof conductive wires 240 such that upon receiving a sensor therein, theone or more receiving ports 213 each function as a conduit forcommunicating information between the additional sensor and thecontroller 220.

In implementations, the elongated strap 210 comprises a fabric. Theelongated strap 210 may comprise or consist of an elastic polyurethanefiber that provides stretch and recovery. For example, the elongatedstrap 210 may comprise or consist of at least one of neoprene, spandex,nylon-spandex, nylon-LYCRA, ROICA, LINEL, INVIYA, ELASPAN, ACEPORA, andESPA. In examples, the elongated strap 210 can comprise or consist of afabric having a biocompatible surface treatment rendering the fabricwater resistant and/or waterproof. In implementations, a portion of theelongated strap 210 comprises a water resistant and/or waterproof fabriccovering and/or encapsulating electronic components including, forexample, the sensing electrodes 212, the treatment electrodes 214, andthe plurality of conductive wires 240, and a portion of the elongatedstrap 210 comprises a water permeable, breathable fabric having arelatively higher moisture vapor transmission rate that the waterresistant and/or waterproof portions.

In implementations, a plurality of conductive wires 240 can be woveninto the warp and weft of the fabric. In implementations, the pluralityof conductive wires 240 can be integrated into the fabric, disposedbetween layers of the elongated strap 210. In implementations, theelongated strap 210 can include the plurality of conductive wires 240integrated into the fabric of the elongated strap 210. Inimplementations, the plurality of conductive wires 240 can comprise orconsist of conductive thread. In examples, the plurality of conductivewires 240 can be integrated in a zigzag or other doubled back pattern soas to straighten as the elongated strap 210 stretches. The zigzag ordoubled-back pattern therefore accommodates for stretching and patientmovement while keeping the plurality of conductive wires 240 fromcontacting the skin of the patient. Integrating the plurality ofconductive wires 240 into the elongated strap 210 reduces and/oreliminates snagging the wire or thread on an external object. In otherexamples, the plurality of conductive wires 240 can be routed on anexterior surface of the elongated strap 210 so as to avoid contactingthe skin of the patient and therefore avoid irritation associated withsuch potential contact. In implementations, the plurality of conductivewires 240 includes two or more conductive wires bundled within aninsulating outer sheath. In implementations, the plurality of conductivewires 240 can be routed along the elongated strap and held securely tothe elongated strap 210 by one or more loops of fabric, closableretention tabs, eyelets and/or other retainers so that the plurality ofconductive wires 240 do not snag on or bulge beneath a patient'sclothing worn over the elongated strap 210.

In implementations of the system 200, the second wearable portion 215 isseparate from the first wearable portion 205. The second wearableportion 215 is configured to be worn over at least one shoulder of thepatient. In implementations, the second wearable portion 215 includes awearable substrate 216, one or more treatment electrodes 214 disposed onthe wearable substrate 216, and at least one conductive wire 242configured to releasably connect the one or more treatment electrodes214 to the controller 220. The one or more treatment electrodes 214includes an anterior treatment electrode 214 a and a posterior treatmentelectrode 214 b. Each of the one or more treatment electrodes 214comprises a corresponding conductive surface configured to contact thepatient's skin at an anterior area and a posterior area of the thoracicregion 105 of the patient.

The one or more treatment electrodes 214 are configured to be assembledinto the wearable substrate 216 or removably attached to the wearablesubstrate, using, for example, pockets formed in or on the wearablesubstrate, hook and loop fasteners, thermoform press fit receptacles,snaps, and magnets, among other restraints. In some implementations, theone or more treatment electrodes 214 can be a permanent portion of thewearable substrate 216. In implementations, the wearable substrate 216comprises or consists of fabric. The fabric may comprise or consist ofan elastic polyurethane fiber that provides stretch and recovery. Forexample, the fabric may comprise or consist of at least one of neoprene,spandex, nylon-spandex, nylon-LYCRA, ROICA, LINEL, INVIYA, ELASPAN,ACEPORA, and ESPA. In implementations, the one or more treatmentelectrodes 214 can be formed of the warp and weft of a fabric forming atleast a layer of the wearable substrate 216. In implementations, the oneor more treatment electrodes 214 are formed from conductive fibers thatare interwoven with non-conductive fibers of the fabric. In someimplementations, the one or more treatment electrodes 214 are metallicplates (e.g. stainless steel) or substrates that are formed as permanentportions of the wearable substrate 216. A metallic plate or substratecan be adhered to the wearable substrate, for example, by a polyurethaneadhesive or a polymer dispersion adhesive such as a polyvinyl acetate(PVAc) based adhesive, or other such adhesive. In examples, the one ormore treatment electrodes 214 are screen printed onto the wearablesubstrate 216 with a metallic ink, such as a silver-based ink.

As previously described, the example devices and systems describedherein are prescribed to be worn continuously and typically for aprescribed duration of time. For example, the prescribed duration can bea duration for which a patient is instructed by a caregiver to wear thedevice in compliance with device use instructions. As noted above, theprescribed duration may be for a short period of time until a follow upmedical appointment (e.g., 1 hour to about 24 hours, 1 day to about 14days, or 14 days to about one month), or a longer period of time (e.g.,1 month to about 3 months) during which diagnostics information aboutthe patient is being collected even as the patient is being protectedagainst cardiac arrhythmias. The prescribed use can be uninterrupteduntil a physician or other caregiver provides a specific prescription tothe patient to stop using the wearable medical device. For example, thewearable medical device can be prescribed for use by a patient for aperiod of at least one week. In an example, the wearable medical devicecan be prescribed for use by a patient for a period of at least 30 days.In an example, the wearable medical device can be prescribed for use bya patient for a period of at least one month. In an example, thewearable medical device can be prescribed for use by a patient for aperiod of at least two months. In an example, the wearable medicaldevice can be prescribed for use by a patient for a period of at leastthree months. In an example, the wearable medical device can beprescribed for use by a patient for a period of at least six months. Inan example, the wearable medical device can be prescribed for use by apatient for an extended period of at least one year.

Continuous use can include continuously monitoring the patient while thepatient is wearing the device for cardiac-related information (e.g.,electrocardiogram (ECG) information, including arrhythmia information,cardiac vibrations, etc.) and/or non-cardiac information (e.g., bloodoxygen, the patient's temperature, glucose levels, tissue fluid levels,and/or pulmonary vibrations). For example, the wearable medical devicecan carry out its continuous monitoring and/or recording in periodic oraperiodic time intervals or times (e.g., every few minutes, every fewhours, once a day, once a week, or other interval set by a technician orprescribed by a caregiver). Alternatively or additionally, themonitoring and/or recording during intervals or times can be triggeredby a user action or another event. The user can be any one of thepatient, remote or local physician, remote or local caregiver, or aremote or local technician, for example.

Because these devices require continuous operation and wear by patientsto which they are prescribed, advantages of the implementations hereininclude use of comfortable, non-irritating construction materials andfeatures designed to enhance patient compliance. Suchcompliance-inducing design features include, for example, deviceergonomics, weight of the components and/or distribution of the weightabout the device or portions of the device, and inconspicuous appearancewhen worn under outer garments (e.g., patient clothing), among others.In some implementations described herein, the devices include variousfeatures that promote comfort while continuing to protect the patientfrom adverse cardiac events. These features can be tailored inaccordance with patient comfort preference and body morphology.

Segregating functionality between a first wearable portion 205 and asecond wearable portion 215 of the system 200 of FIG. 6A providesadvantages of increased patient comfort and device modularity whilemitigating motion artifacts associated with the plurality ECG sensingelectrodes 212 shifting or sliding against the skin of the patientduring a continuous duration of wear. Because the first wearable portion205 includes sensors for monitoring one or more physiological conditionsof the patient, e.g. the plurality of ECG sensing electrodes 212 and theadditional sensor, the first wearable portion 205 is configured to beworn continuously or nearly continuously for a prescribed duration ofwear. As previously described, that elongated strap 210 encircles thethoracic region 105 of the patient. As shown in FIG. 6B, inimplementations, the elongated strap 210 has a vertical span V4 from abottom circumferential edge 265 to a top circumferential edge 260 in arange of 1 to about 15 centimeters. For example, in implementations, thevertical span V4 is between 2 to 12 centimeters. For example, inimplementations, the vertical span V4 is between 3 to 8 centimeters. Theelongated strap 210 exerts a radial compression force in a range of0.025 psi to 0.75 psi to the thoracic region 105 of the patient. Inimplementations the second wearable portion 215 comprises a compressionforce relatively lower than the compression force of the elongated strap210. In implementations the second wearable portion 215 comprises one ormore compression forces relatively lower than the compression force ofthe elongated strap 210. In implementations the second wearable portion215 comprises an average compression force relatively lower than thecompression force of the elongated strap 210. Compression forces of themedical device can be determined, for example, using one or morepressure sensors and systems as described above with regard to the band110 of FIG. 2A. In implementations, the second wearable portion 215 isconfigured to be worn for a cumulative duration less than or equal tothe duration of wear of the first wearable portion 205 as will bedescribed subsequently.

Because the elongated strap 210 has a vertical span V4 in a range of 1to about 15 centimeters (e.g., 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm,8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm) and is configuredto be worn about the thoracic region 105 at a position or a range ofpositions between around about the T1 thoracic region to about the T12thoracic region, the system 200 accommodates a variety of body sizes andmorphologies by avoiding anatomically diverse regions of the human body.Similarly to the embodiment shown in FIGS. 3A-B, the elongated strap 210is configured to be worn, for example, about the thoracic region at aposition that can avoid a chest area and any protruding stomach area. Inimplementations, the strap 210 is configured to be worn within a T5thoracic vertebra region and a T11 thoracic vertebra region. Inimplementations, the strap 210 is configured to be worn within a T8thoracic vertebra region and a T10 thoracic vertebra region. By securingthe elongated strap 210 on the thoracic region 105 in this range, thesystem 200 immobilizes the ECG sensing electrodes 212 and any additionalsensor against the skin of the patient in a relatively smooth sensorsurface to skin surface arrangement. This ensures complete sensorcontact with the skin of the patient while reducing or eliminatingmotion artifacts regardless of patient gender or body type. Thisplacement of the elongated strap 210 also avoids interference with apatient's arms and prevents movement of the elongated strap 210 as thepatient goes about a daily routine, moving, shifting, bending, twisting,lifting arms, etc. The elongated strap 210 is discreetly and comfortablysecured without covering a substantial portion of the patient's thoracicregion 105. A substantial portion can be for example, 25%, 30%, 35%,40%, 45%, 50% or more than 50% of the thoracic region 105.

The second wearable portion 215 can be worn for a portion of theprescribed cumulative duration of wear as will be described subsequentlywith regard to FIGS. 8A and 8B. Because the second wearable portion 215comprises one or more treatment electrodes 214, the compression forcesof the second portion need not be as great as those of the firstwearable portion 205 having thereon or therein sensing electrodessensitive to motion artifacts. In implementations, the first wearableportion 205 can be worn independently of the second wearable portion 215and can be configured to provide monitoring functionality. Inimplementations, the first wearable portion 205 includes one or morereceiving ports 213 configured to receive an additional sensor. Becausethe first wearable portion 205 is a compression device, the firstwearable portion 205 supports monitoring sensors and/or sensing deviceswithout the need for potentially irritating skin adhesives. Suchadhesives are generally used to apply independently worn sensors and/ordevices, but the first wearable portion 205 is immobilized bycompression forces, reducing or eliminating a need for adhesives.

As previously described, in implementations, the system 200 is a cardiacmonitoring and treatment system and the first wearable portion 205comprises a plurality of ECG sensing electrodes 212. In implementations,the system 200 includes an ECG acquisition circuit in communication withthe plurality of ECG sensing electrodes 212 and the at least oneprocessor 218 of the controller 220. The ECG acquisition circuit isconfigured to provide ECG information for the patient based on thesensed ECG signal. In one implementation, the ECG acquisition circuit iscollocated with the plurality of ECG sensing electrodes 212. In oneimplementation, the EGC acquisition circuit is located on the devicecontroller 220. In implementations, the system 200 includes a connectionpod 230 in wired connection with one or more of the plurality of ECGsensing electrodes 212 and the ECG acquisition circuitry. In someexamples, the connection pod 230 includes at least one of the ECGacquisition circuitry and a signal processor configured to amplify,filter, and digitize the cardiac signals prior to transmitting thecardiac signals to the controller 220. In implementations, the systemcan include at least one ECG sensing electrode 212 configured to beadhesively attached to an upper portion of the thoracic region 105,above the elongated strap, the at least one ECG sensing electrode 212being in wired communication with at least one of the connection pod andthe controller 220.

As previously described, the second wearable portion 215 is configuredto be worn for a cumulative duration less than or equal to the durationof wear of the first wearable portion 205. In implementations of thesystem 200, the at least one processor 218 is configured to predict alikelihood of a cardiac event based on an analysis of the ECGinformation and provide a notification to the patient to wear the secondwearable portion 215 upon detecting the impending cardiac event. Inimplementations, the controller 220 includes a set of instructionscomprising a Sudden Cardia Arrhythmia (SCA) risk analysis assessor 219.The SCA risk analysis assessor 219 provides a set of instructions to theprocessor for computing an SCA Risk score and analyzing whether thelikelihood of an SCA occurring is high or not. Because the SCA riskanalysis assessor 219 is predictive, the at least one processor 218 candetermine, for example, a high likelihood of an SCA occurring in thenext two weeks and prompt the controller 220 to provide an instructionand/or an alert to the patient to wear the second wearable portion 215comprising the one or more treatment electrodes 214.

As shown in FIGS. 8A and 8B, in implementations, the at least oneprocessor 218 receives S805 the patient ECG signal from the plurality ofECG sensing electrodes 212 and computes S810 a sudden cardiac arrhythmia(SCA) risk score (S) in method 800. In implementations, the SCA riskscore is computed based on at least one of ECG metrics passed from anECG analyzer and patient demographic and clinical data. The ECG metricscan include, for example, one or more of the ECG metrics of table 4.

TABLE 4 Heart Rate HR_(avg) Average heart rate HR_(min) Minimum heartrate HR_(max) Maximum heart rate Heart Rate Variability NN_(avg) Averagenormal-to-normal interval in seconds NN_(min) Minimum normal-to-normalinterval in seconds NN_(max) Maximun normal-to-normal interval inseconds NN_(sd) Standard deviation of normal-to-normal intervals inseconds RMS Square root of the mean squared difference of successivenormal-to-normal intervals measured in seconds NN50 Number of successivenormal-to-normal intervals greater than 50 ms per minute. pNN50Percentage of normal-to-normal intervals greater than 50 ms per minute.QRS Duration QRS_(med) Median QRS duration QRS_(sd) Standard deviationof QRS duration PVCs PVC_(count) Number of PVCs nsvtCount Number ofconsecutive heartbeat sequences of PVCs

The patient demographic and clinical data include one or more of themetrics of table 5.

TABLE 5 Demographic and clinical metrics Age Gender Explant ofimplantable cardioverter defibrillator (ICD) coronary artery bypassgraft (CABG) congestive heart failure (CHF) hypertrophic cardiomyopathy(HCM) Myocardial infarction (MI) ventricular tachycardia/ventricularfibrillation (VT/VF)

The computed SCA Risk Score (S) is then compared S815 against auser-defined risk score threshold (T). If S is less than T, the at leastone processor 218 continues to receive S805 patient ECG signals foranalysis. If S is greater than T, the processor prompts S820 anotification to wear the second wearable portion 215.

In implementations, computing the SCA Risk Score (S) associated withestimating a risk of a potential cardiac arrhythmia event for thepatient includes applying the sets of ECG metrics and patientdemographic and clinical data to one or more machine learning classifiermodels. In some implementations, a machine learning classifier can betrained on a large population, for example, a population that can rangefrom several thousand to tens of thousands of patient records comprisingelectrophysiology, demographic and medical history information. Themachine learning tool can include but is not limited to classificationand regression tree decision models, such as random forest and gradientboosting, (e.g., implemented using R or any otherstatistical/mathematical programming language). Any other classificationbased machine learning tool can be used, including neural networks andsupport vector machines. Because the machine learning tool may becomputationally intensive, some or all of the processing for the machinelearning tool may be performed on a server that is separate from themedical device. Examples of risk prediction methods and classifiers aredescribed in, for example, U.S. Publication No. US 2016/0135706 entitled“Medical Premonitory Event Estimation,” the entire content of which isincorporated herein by reference.

In implementations, the system 200 includes an output device, such asthe output device 1216 of the implementation of the controller 220 ofFIG. 7, and the notification to wear the second wearable portion 215 isprovided via the output device 1216. In implementations the outputdevice 1216 is a display and/or speaker of the controller 220 configuredto provide a visible and/or audible alarm. In implementations, thecontroller 220 includes a speaker for providing an alarm sound and/orspoken instructions alerting the patient to wear the second wearableportion 215. The alarm sound can be unique from an alarm soundindicating imminent treatment and in implementations is provided withincreasing volume or frequency depending on the urgency of the predictedSCA. If the at least one processor 218 determines the SCA is likely tooccur within two weeks but not imminently, the alarm may be softer andrepeated less frequently than a more urgently impending event. Forexample, if the at least one processor 218 determines the SCA is likelyto occur within a week, the notification can include a series of alertsprovided at 1 minute increments at a first decibel level. If theprocessor determines the SCA is likely to occur beyond one week butwithin two weeks, the series of alerts are provided at 10 minuteincrements at a second decibel level that equivalent to or quieter thanthe first decibel level.

The notification can comprise an instruction to connect the at least oneconductive wire 242 of the second wearable portion 215 to the controller220. In implementations, the at least one processor is configured toinitiate delivery of a therapeutic shock via the one or more treatmentelectrodes 214. Accordingly, the one or more treatment electrodes 214need to be operatively connected to the controller 220. Inimplementations, the at least one processor 218 can be configured todetect successful connection of the at least one conductive wire 242. Inimplementations, the at least one processor 218 provides, via the outputdevice, an indication of successful connection of the at least oneconductive wire 242 of the second wearable portion 215 to the controller220. If connection of the at least one conductive wire 242 is notdetected within a threshold period of time, the at least one processor218 provides an audible and/or visible alert to the patient. Inimplementations, this process repeats until the one or more treatmentelectrodes 214 of the second wearable portion 215 are operably connectedto the controller 220 and available for providing a therapeutic shock tothe patient as initiated by the at least one processor 218.

In implementations, the system 200 is configured for use with a remoteserver, and one or more functions of the at least one processor 218 areperformed by the remote server. Additionally, one or more of the ECGmetrics, patient demographic and clinical data, and threshold values canbe stored on a remote database in communication with and accessible bythe remote server. For example, a processor of the remote server canexecute the instructions of the SCA Risk Analysis Assessor and providethe output to the at least one processor 218 of the controller 220.Alternatively or additionally, a processor of the remote server canprovide the output to a computing device of a physician or caregiver.The computing device can provide an audible and/or visible notificationto the physician or caregiver to instruct the patient on wearing thesecond wearable portion 215.

In implementations, splitting computation between the controller 220 anda remote server 300 assists with reducing the overall size andconstruction of the controller 220. As shown in FIG. 9A, the controller220 can further be reduced in size as compared to the controller ofFIGS. 6A and 9B, by distributing controller components throughout thefirst and second wearable portions 205, 215. As described with regard toFIG. 7 and as will be described in greater detail subsequently,implementations of a wearable cardiac monitoring and treatment system200 include the controller 220 comprising one or more of the followingcomponents: a therapy delivery circuit 1130 including a polarityswitching component such as an H-bridge 1228, a data storage 1207, anetwork interface 1206, a user interface 1208, at least one battery1140, a sensor interface 1202 that includes, for example, an ECG dataacquisition and conditioning circuit, an alarm manager 1214, the leastone processor 218, and one or more capacitors 1135. As shown in FIG. 9A,in implementations, the high voltage components such as the one or morecapacitors 1135 and therapy delivery circuit 1130 can be redistributedto the second wearable portion 215. For example, the one or moretreatment electrodes 214 can include one or more of these high voltagecomponents. Redistributing these bulkier and heavier components to thesecond wearable portion 215 reduces the overall size and of thecontinuously worn controller 220. Because the controller 220 is worncontinuously or substantially continuously throughout the duration ofwear of the system 200 and because the second wearable portion 215 isworn only when an SCA Risk Assessment Score (S) exceeds a threshold (T),the heavier portions are only worn when necessary. This further assistswith overall patient comfort and encourages patient compliance withwearing the first wearable portion 205 for the prescribed duration ofwear.

In implementations, as shown in the timeline of FIG. 8B, the cumulativeduration of wear 850 of the first wearable portion 205 is equal to orgreater than the cumulative duration of wear 852 a, 852 b of the secondwearable portion 215 because the second wearable portion 215 is wornonly when the patient is prompted by the system 200. Although aphysician may prescribe the system 200 for a duration of wear 850, onlythe first wearable portion 205, the monitoring portion, need be worncontinuously throughout that prescribed duration of wear 850. As shownon the example timeline of FIG. 8B, the patient is not wearing thesecond wearable portion during an initial span 851 beginning at thestart of the duration of wear 850 and lasting until S>T, about a weekand a half past the one month mark. The second wearable portion 215 isworn when an SCA Risk Score (S) exceeds a threshold (T), but because themonitoring is continuous, the at least one processor 218 may detect animprovement in the patient's condition. In implementations, if the SCARisk Score (S) improves during the prescribed duration of wear of thefirst wearable portion 205 so that S is less than T, the at least oneprocessor 218 can notify the patient to remove the second wearableportion 215. For example, in the timeline of FIG. 8B, the SCA riskanalysis assessor outputs S<T about one and a half weeks past the secondmonth mark. In implementations, the at least one processor 218calculates a wait period 853 of about another 1-2 weeks and continuescomputing the SCA Risk Score (S) for the duration of the wait period 853to ensure the patient's condition is stable. At the end of the waitperiod, the at least one processor 218 can provide a notification thatthe patient may remove the second wearable portion 215 during a secondperiod 854 of not wearing the second wearable portion 215 because S hasremained less than T. In implementations, S must remain less than Twithout fluctuation and within a user defined tolerance range (e.g. 5%or more less the threshold T) during the wait period 853 in order forthe at least one processor 218 to provide a notification to remove thesecond wearable portion 215. In this example, the at least one processor218 computes an SCA Risk Score S greater than T at month 4 and againprompts a notification to wear the second wearable portion 215. Becausemonitoring and analysis is continuous throughout the duration of wear850, the SCA Risk Score S may remain greater that T until the end of theprescribed duration of wear 850, at which time the physician orcaregiver may re-evaluate treatment options for the patient. The system200 therefore continuously monitors the patient's physiologicalcondition and protects the patient from harm while also accounting forpatient comfort by avoiding unnecessary wear of the second wearableportion 215.

Patient comfort is also achieved by customizing one or more features ofthe elongated strap 210 for each patient's preferences and bodymorphology. Returning to FIGS. 6A-B, the elongated strap 210 can besized to fit about the thoracic region 105 of the patient by matchingthe length the elongated strap 210 to one or more circumferentialmeasurements of the thoracic region 105 during an initial fitting. Forexample, in an initial fitting, a caregiver, physician or patientservice representative (PSR) can measure the circumference of thethoracic region 105 of the patient at one or more locations disposedabout the thoracic region 105 between about the T1 thoracic region andthe T12 thoracic region, and select an elongated strap 210 having alength L2 within a range of 2-25% longer than the largest measuredcircumference. For example, the strap 210 can be configured to be wornwithin a T5 thoracic vertebra region and a T11 thoracic vertebra region.For example, t the strap 210 can be configured to be worn within a T8thoracic vertebra region and a T10 thoracic vertebra region. Having theelongated strap 210 be longer than the largest measured circumference ofthe thoracic region 105 can provide comfort advantages of loosening andtightening the elongated strap 210 to accommodate fluctuations in bodymass throughout the prescribed duration of wear. Additionally, inembodiments of the system 200 having a fastener 247 configured to securethe elongated strap 210 about the thoracic region 105, the patient canloosen or reposition the elongated strap 210 around one or morepositions along the thoracic region 105 between about the T1 thoracicregion and T12 thoracic region. In implementations, at least onefastener 247 is disposed on a first end 245 a of the elongated strap 210for adjoining a second end 245 b of the elongated strap 210 in securedattachment about the thoracic region 105 of the patient. Inimplementations, the fastener 247 is an adjustable latching mechanismconfigured to secure and tighten the elongated strap 210 about thethoracic region 105 of the patient.

Additionally or alternatively, the elongated strap 210 or other supportelements of preceding and subsequently described implementations, suchas appendages 111 of FIG. 2A and 211 of FIGS. 9A-B, and sash 410 of FIG.14, can have proportions and dimensions derived from patient-specificthoracic 3D scan dimensions so as to provide conformally fitted supportelements shaped to fit the particular patient's exact body shape,thereby providing a much higher degree of comfort than an off-the-shelfgarment. The 3D scan dimensions may be generated from a threedimensional imaging system such as a 3D surface imaging technology withanatomical integrity, for instance the 3dMDthorax System by 3dMD LLC,Atlanta Ga.

The three-dimensional imaging system can comprise one or more of adigital camera, RGB camera, digital video camera, red-green-blue sensor,and/or depth sensor for capturing visual information and static or videoimages of the rescue scene. In some examples, the three-dimensionalimaging system can comprise both optical and depth sensing components aswith the Kinect motion sensing input device by Microsoft, or the AppleTrueDepth 3D sensing system which may include an infrared camera, floodilluminator, proximity sensor, ambient light sensor, speaker,microphone, 7-megapixel traditional camera, and dot projector (whichprojects up to 30,000 points on an object during a scan).

The patient-specific thoracic 3D scan dimensions can be input intocustom-tailoring software such as ACCUMARK MADE-TO-MEASURE and ACCUMARK3D by Gerber Technology of Tolland, CT, or EFI Optitex 2D and 3Dintegrated pattern design software by EFI Optitex of New York, N.Y. Thedimensions as well as three-dimensional surfaces can also be input intoa 3D printer such as the FORMLABS FORM 3L 3D printer (by Formlabs ofSomerville, MA) using the FORMLABS elastic resin to generate strap orother support elements that conform to the patient's body shape. Theelastic resin comprises a shore durometer of between about 40 A-80 A(e.g. 40 A, 45 A, 50 A, 55 A, 60 A, 65 A, 70 A, 75 A, 80 A).

From a 3-dimensional scan of the thoracic region 105 of the patient, anelongated strap 210 or other support element can be sized to fitproportions and dimensions of the thoracic region 105 in a nested fitthat conforms to the specific patient's body shape. In implementations,for example, various body size measurements and/or 3D images may beobtained of at least a portion of the patient's body, and one or moreportions of the elongated strap 210 or other support element can beformed of a plastic, polymer, or woven fabric to have contoursaccommodating one or more portions of the thoracic region, or otheranatomical region such as arms, neck, etc. conforming to the specificpatient's body shape. For example one or more portions of the elongatedstrap 210 or other support element may be 3D printed from, for example,any suitable thermoplastic (e.g., ABS plastic) or any elastomeric and/orflexible 3D printable material. For example the elongated strap 210 mayinclude at least two curved rigid or semi-rigid portions for engagingthe patient's sides, under the arms. The at least two curved portionsadd rigid structure that assists with preventing the elongated strap 210from shifting or rotating about the thoracic region. This stabilityprovides consistency of sensor signal readings and prevents noiseassociated with sensor movement.

As described previously with regard to the embodiments of FIGS. 2A-B, inimplementations, the elongated strap 210 comprises at least one visibleindicator 249 of elongated strap 210 tension disposed on a surface ofthe elongated strap 210. For example, the visible indicator 249 can be acolor changing indicator incorporated in the elongated strap 210indicating whether the elongated strap 210 is too loose, overtightened,or compressed within the range of compressive forces. As the elongatedstrap 210 stretches, the material forming the visible indicator 249, forexample, can change color between blue, indicating over-tensioning orunder-tensioning, and yellow or green, indicating proper tensioning forsimultaneously enabling sensor readings and patient comfort. In oneimplementation, the visible indicator 249 can comprise one or morestretchable, multilayer smart fibers disposed in or on the elongatedstrap 210. The one or more smart fibers change color from red, toorange, to yellow, to green and to blue as strain on the fiberincreases. Providing a visible indication directly on the elongatedstrap 210 enables a patient to adjust or reapply the strap 210 so thatthe plurality of ECG sensing electrodes 212 and the one or moretreatment electrodes 214 are properly positioned and immobilized on thethoracic region 105 and so that the strap 210 isn't overtightened andapplying compressive forces in the thoracic region 105 to a level ofpatient discomfort. In other implementations, the elongated strap 210can include a mechanical strain gauge in or on the elongated strap 210.The mechanical strain gauge can be communicatively coupled to theplurality of conductive wires 240 such that the controller 220 providesan audible and/or visible indication of whether the elongated strap 210is over-tightened, too loose, or within the range of compression forcesenabling effective use and wear comfort.

In implementations, the elongated strap 210 comprises an unbroken loopcomprising a stretchable fabric. The elongated strap 210 can beconfigured to stretch over the shoulders or hips of the patient andcontract when positioned about the thoracic region 105. Inimplementations, the stretchable fabric comprises at least one of nylon,LYCRA, spandex, and neoprene. During an initial fitting, the physician,caregiver, or PSR can select an elongated strap 210 sized to fit thepatient. For example, the physician, caregiver, or PSR can measure acircumference about one or more locations of the thoracic region 105.The physician, caregiver, or PSR can select an elongated strap 210having a circumference within about 75% to about 95% of the measurementof the one or more locations about the thoracic region 105. In someimplementations, the elongated strap 210 comprises an elasticizedthread. In some implementations, the elongated strap 210 comprises anelasticized panel disposed in the elongated strap 210, the elasticizedpanel comprising a portion of the elongated strap 210 spanning less thana total length of the elongated strap 210. For example, the elongatedstrap 210 can include one or more mechanically joined sections forming acontinuous length L2 or unbroken loop. The one of the one or moresections can comprise a stretchable fabric and/or elasticized threadinterspersed with non-stretchable or relatively less stretchableportions. In other embodiments, the elongated strap 210 can include acompression an adjustable tension element, such as one or more cordsdisposed in the elongated strap 210 and configured to be tensioned andheld in tension by one or more pull stops. In all embodiments, theelongated strap 210 can include one or more visible or mechanicaltension indicators configured to provide a notification of the elongatedstrap 210 exerting compression forces against the thoracic region 105 ina range from 0.025 psi to 0.75 psi.

In implementations, the elongated strap 210 comprises a breathable,skin-facing layer including at least one of a compression padding, asilicone tread, and one or more textured surface contours. Thebreathable material and compression padding enable patient comfortthroughout the duration of wear and the silicon tread and/or one or moresurface contours assist with immobilizing the elongated strap 210relative to the skin surface of the thoracic region.

Implementations of the elongated strap 210 in accordance with thepresent disclosure may exhibit a moisture vapor transmission rate (MVTR)of, for example, between about 600 g/m2/day and about 1,400 g/m2/daywhen worn by a subject in an environment at room temperature (e.g.,about 25° C.) and at a relative humidity of, for example, about 70%. Inimplementations, the elongated strap 210 has a water vapor permeabilityof 100 g/m²/24 hours, as measured by such vapor transmission standardsof ASTM E-96-80 (Version E96/E96M-13), using either the “in contact withwater vapor” (“dry”) or “in contact with liquid” (“wet”) methods. Suchtest methods are described in in U.S. Pat. No. 9,867,976, titled“LONG-TERM WEAR ELECTRODE,” issued on Jan. 16, 2018 (hereinafter the“'976 Patent”), the disclosure of which is incorporated by referenceherein in its entirety. In implementations, the elongated strap 210comprises one or more moisture wicking fabrics for assisting with movingmoisture away from the skin of the thoracic region 105 and improvingpatient comfort throughout the prescribed duration of wear.

In implementations, the elongated strap 210 includes low skin-irritationfabrics and/or adhesives. In embodiments, the elongated strap 210 may beworn continuously by a patient for a long-term duration (e.g., durationof at least one week, at least 30 days, at least one month, at least twomonths, at least three months, at least six months, and at least oneyear) without the patient experiencing significant skin irritation. Forexample, a measure of skin irritation can be based on skin irritationgrading of one or more as set forth in Table C.1 of Annex C of AmericanNational Standard ANSI/AAMI/ISO 10993-10:2010, reproduced above in Table1.

The second wearable portion 215 similarly can comprise or consist of lowskin irritation fabrics. Additionally, the substrate 216 of secondwearable portion 215 can be lightweight and less compressive than theelongated strap 210 of the first wearable portion 205. Inimplementations, such as those of FIGS. 6A-B and 9A-13B, the secondwearable portion 215 comprises at least one of a shirt, a vest, abandeau, a pinnie, a butterfly harness, a yoke, and a dickie. The firstand second wearable portions 205, 215 are configured to be worn beneatha clothing of the patient. By maintaining and minimizing the substrate216 of the second wearable portion 215, the system 200 further minimizespatient discomfort and visibility of the system 200 when worn beneathouter garments (e.g., the patient's clothing). For example, as shown inthe implementation of FIGS. 10A-B, the second wearable portion 215 cancomprise a belt 271 and suspenders 217 for supporting one or moretreatment electrodes 214 and one or more additional sensors, such as ap-wave sensor 223 located on an upper half of the thoracic region 105.In implementations, as shown in FIGS. 11A-B, the second wearable portion215 can be a holster worn about the armpits and supported by thepatient's shoulders. In implementations, as shown in FIGS. 12A-B, thesecond wearable portion 215 can be a butterfly harness worn about thearmpits and supported by the patient's shoulders.

Additionally or alternatively, in implementations, the first wearableportion 205 and/or the second wearable portion 215 can includeadditional sensors and in implementations, one or both of the firstwearable portion 205 and second wearable portion 215 can include variousstructural elements for supporting one or more additional sensors of thesystem 200. For example, the first wearable portion 205 further caninclude an appendage 211 mechanically attached to the elongated strap210. In implementations, the appendage is a flap, similar to theanterior and posterior appendages 150, 155 of FIGS. 2A-B. Inimplementations, as shown in FIGS. 6A and 9A the appendage 211 is anover-the-shoulder sash. In implementations, as shown in FIG. 9B, theappendage 211 is a pair of over-the shoulder sashes crossing over theanterior area of the thoracic region 105. In implementations, theappendage 211 is monolithically formed with the elongated strap 210 andtherefore non-separable from the elongated strap 210. Inimplementations, the appendage 211 is configured to be affixed to theelongated strap 210. The appendage 211 can be affixed to the elongatedstrap by permanent fasteners, such as, for example rivets, stitches,heat welds, and adhesives. In other implementations, one or both ends ofthe appendage 211 can be affixed to the elongated strap 210 byreleasable fasteners, such as zippers, hook and loop fasteners, buttons,and snaps. The appendage 211 can be adjustable in length and cancomprise a stretchable fabric to hold the appendage 211 in compressionagainst the thoracic region 105. For example, the appendage 211 cancomprise a fabric comprising or consisting of an elastic polyurethanefiber that provides stretch and recovery. For example, the fabric maycomprise or consist of at least one of neoprene, spandex, nylon-spandex,nylon-LYCRA, ROICA, LINEL, INVIYA, ELASPAN, ACEPORA, and ESPA. Inimplementations, the appendage 211 can be optionally affixed to theelongated strap to provide additional functionality as prescribed by aphysical and/or to provide the patient an opportunity to remove,launder, swap out, and/or replace the appendage 211. For example, if theappendage 211 starts to stretch and loosen, the patient may prefer toremove the appendage 211 and don a new, more taught replacement.

In implementations, the appendage 211 is configured to be continuouslyworn about the thoracic region 105 of the patient and comprises at leastone additional ECG sensing electrode 212 b in communication with theplurality of conductive wires 240 of the elongated strap 210. The atleast one additional ECG sensing electrode 212 b is configured to sensethe ECG signal of the patient in conjunction with the plurality of ECGsensing electrodes 212 of the elongated strap 210. As previouslydescribed with regard to the device of FIG. 5, an appendage 111comprises at least one treatment electrode 114 b in communication withthe at least one processor, the at least one treatment electrode 114 bconfigured to provide a therapeutic shock. In such an implementation,the at least one treatment electrode 114 b is in wired communicationwith the plurality of conductive wires of the band 110. Similarly, theappendage 211 of FIGS. 9A-B can include at least one of one or morepermanently affixed and/or selectively added additional treatmentelectrodes, additional ECG sensing electrodes 212 b, p-wave sensors, andother physiological sensors. In the implementations of FIGS. 9A-9B, forexample, the appendage 211 comprises thereon an additional ECG sensingelectrode 212 b positioned in an upper anterior region of the thoracicregion 105, such that the at least one processor 218 can monitor astandard EGC signal lead. Additionally, in the implementations of FIGS.9A-9B the appendage includes one or more receiving ports 213 a-bconfigured to receive one or more additional sensors. The additional oneor more sensors can be, for example, one or more physiological sensorsfor detecting one or more of pulmonary vibrations (e.g., usingmicrophones and/or accelerometers), breath vibrations, sleep relatedparameters (e.g., snoring, sleep apnea), and tissue fluids (e.g., usingradio-frequency transmitters and sensors). The one or more additionalsensors of the appendage 211 can be, for example, one or morephysiological sensors including a pressure sensor for sensingcompression forces of the garment, SpO2 sensors, blood pressure sensors,bioimpedence sensors, humidity sensors, temperature sensors, andphotoplethysmography sensors. In some examples, the one or morereceiving ports 213 a-b can also be configured to receive one or moremotion and/or position sensors. For example, the additional one or moresensors can be motion sensors including accelerometers for monitoringthe movement of the patient's torso in x-, y- and z-axes to determine amovement of the patient, gait, and/or whether the patient is upright,standing, sitting, lying down, and/or elevated in bed with pillows. Incertain implementations, one or more gyroscopes may also be provided tomonitor an orientation of the patient's torso in space to provideinformation on, e.g., whether the patient is lying face down or face up,or a direction in which the patient is facing.

In the implementation of FIGS. 10A-B, the one or more additional sensorscan be supported by the second wearable portion 215. For example, thesuspenders 217 of the second wearable portion of FIG. 10A have disposedthereon an EGS sensor 212 and a p-wave sensor 223 located in an upperanterior portion of the thoracic region for optimal positioning forsensor readings. Similarly, the implementations of the second portion215 of FIGS. 10B-12B include one or more additional sensors, includingat least an ECG sensing electrode 212.

As previously described the first wearable portion 205 is continuouslyworn or substantially continuously worn about the thoracic region 105throughout the prescribed duration of wear. In some implementations,such as that of FIG. 13, the monitoring portion of the system 200 caninclude a first wearable portion 205 including an elongated strap 210 asdescribed previously in embodiments and a second, separate strap 206configured to be draped around the upper portion of the thoracic region105. The separate strap 206 is configured to support one or moreaddition sensors such as a p-wave sensor 223 and an additional ECGsensing electrode 212 configured to detect an ECG signal of the patientin conjunction with the one or more ECG sensing electrodes of theelongated strap 210. This second strap 206 provides optimal placement ofthe additional sensors for detecting or more conditions of the patientwithout the use of potentially irritating adhesives.

While the first wearable portion 205 can provide, in implementations,various combinations of physiological sensors, in other implementations,the device can be a unitary wearable device include all sensing andtreatment sensors. Similar to the device 100 of FIGS. 2A-2B, the cardiacmonitoring and treatment device 400 of FIG. 14 includes a continuouslyworn, cross-body sash 410 worn over a shoulder of a patient and aroundan opposite side of the patient. In implementations, the sash 410 isconfigured to be worn over a shoulder of a patient, encircling athoracic region 105, extending from over the first shoulder of thepatient across an anterior area of the thoracic region 105 to anopposite lateral side of the thoracic region 105 under the secondshoulder of the patient adjacent to the axilla, and further extendingacross a posterior area of the thoracic region 105 from under the secondshoulder to over the first shoulder. The device 400 comprises aplurality of electrodes and associated circuitry disposed about the sash410. The plurality of electrodes can include at least one pair ofsensing electrodes 412 disposed about the sash 410 and configured to bein electrical contact with the patient. The at least one pair of sensingelectrodes 412 can be configured to detect one or more cardiac signalssuch as ECG signals. An example ECG sensing electrode 412 includes ametal electrode with an oxide coating such as tantalum pentoxideelectrodes, as described in, for example, U.S. Pat. No. 6,253,099entitled “Cardiac Monitoring Electrode Apparatus and Method,” thecontent of which is incorporated herein by reference. The device 400 caninclude an ECG acquisition circuit in communication with the at leastone pair of ECG sensing electrodes 412 and configured to provide ECGinformation for the patient based on the sensed ECG signal. Inimplementations, the at least one pair of sensing electrodes can includea driven ground electrode, or right leg drive electrode, configured toground the patient and reduce noise in the sensed ECG signal.

The plurality of electrodes can include at least one pair of treatmentelectrodes 414 a and 414 b (collectively referred to herein as treatmentelectrodes 414) coupled to a treatment delivery circuit. The at leastone pair of treatment electrodes 414 can be configured to deliver anelectrotherapy to the patient. For example, one or more of the at leastone pair of treatment electrodes 414 can be configured to deliver one ormore therapeutic defibrillating shocks to the body (e.g., the thoracicregion 105) of the patient when the medical device 100 determines thatsuch treatment is warranted based on the signals detected by the atleast one pair of ECG sensing electrodes 412 and processed by themedical device controller 420. Example treatment electrodes 414 include,for example, conductive metal electrodes such as stainless steelelectrodes that include, in certain implementations, one or moreconductive gel deployment devices configured to deliver conductive gelto the metal electrode prior to delivery of a therapeutic shock. Inimplementations, a first one of the at least one pair of treatmentelectrodes 414 a is configured to be located within an anterior area ofthe thoracic region 105 and a second one of the at least one pair oftreatment electrodes 414 b is configured to be located within aposterior area of the thoracic region 105 of the patient. In someimplementations, the anterior area can include a side area of thethoracic region 105.

In some examples, at least some of the plurality of electrodes andassociated circuitry of the device 100 can be configured to beselectively affixed or attached to the sash 410 which can be worn aboutthe patient's thoracic region 105. In some examples, at least some ofthe plurality of electrodes and associated circuitry of the device 400can be configured to be permanently secured into the sash 410. Inimplementations, the plurality of electrodes are manufactured asintegral components of the sash 410. For example, the at least one pairof treatment electrodes 414 and/or the at least one pair of ECG sensingelectrodes 412 can be formed of the warp and weft of a fabric forming atleast a layer of the sash 410. In implementations, the at least one pairof treatment electrodes 414 and at least one pair of ECG sensingelectrodes 412 are formed from conductive fibers that are interwovenwith non-conductive fibers of the fabric.

In implementations, the device 400 includes a controller 420 includingan ingress-protected housing, and a processor disposed within theingress-protected housing. The processor is configured to analyze theECG information of the patient from the ECG acquisition circuit anddetect one or more treatable arrhythmias based on the ECG information,and cause the treatment delivery circuit to deliver the electrotherapyto the patient on detecting the one or more treatable arrhythmias. Themedical device controller 420 can be operatively coupled to the at leastone pair of ECG sensing electrodes 412, which can be affixed to the sash410. In embodiments, the at least one pair of ECG sensing electrodes 412are assembled into the sash 410 or removably attached to the garment,using, for example, hook and loop fasteners, thermoform press fitreceptacles, snaps, and magnets, among other restraints. In someimplementations, as described previously, at least one pair of ECGsensing electrodes 412 can be a permanent portion of the sash 410. Themedical device controller 420 also can be operatively coupled to the atleast one pair of treatment electrodes 414. For example, the at leastone pair of treatment electrodes 414 can also be assembled into the sash410, or, as described previously, in some implementations, the at leastone pair of treatment electrodes 414 can be a permanent portion of thesash 410. Optionally, the device can include a connection pod 430 inwired connection with one or more of the plurality of electrodes andassociated circuitry. In some examples, the connection pod 430 includesat least one of the ECG acquisition circuit and a signal processorconfigured to amplify, filter, and digitize the cardiac signals prior totransmitting the cardiac signals to the medical device controller 420.In implementations, the device 400 can include at least one ECG sensingelectrode 412 configured to be adhesively attached to the upper portionof the thoracic region 105, above the sash 410, the at least one pair ofECG sensing electrodes 412 being in wired communication with the ECGacquisition circuitry and at least one of the connection pod and thecontroller 420.

In implementations, the device includes a conductive wiring 440configured to communicatively couple the controller 420 to the pluralityof electrodes and associated circuitry disposed about the sash 410. Inimplementations, the conductive wiring 440 can be woven into the warpand weft of the fabric. In implementations, the conductive wiring 440can be integrated into the fabric, disposed between layers of the sash.In implementations, the conductive wiring 440 can include one or moreconductive threads integrated into the fabric of the sash 410. Inexamples, the one or more conductive threads can be integrated in azigzag or other doubled back pattern so as to straighten as the sash 410stretches. The zigzag or doubled-back pattern therefore accommodates forstretching and patient movement while keeping the one or more conductivethreads from contacting the skin of the patient. Integrating theconductive wiring 440 into the sash 410 reduces and/or eliminatessnagging the wire or thread on an external object. In other examples,the conductive thread can be routed on an exterior surface of the sash410 so as to avoid contacting the skin of the patient and thereforeavoid irritation associated with such potential contact. Inimplementations, the conductive wiring 440 includes two or moreconductive wires bundled within an insulating outer sheath. Inimplementations, the conductive wiring 440 can be routed along the sash410 and held securely to the sash 410 by one or more loops of fabric,closable retention tabs, eyelets and/or other retainers so that theconductive wiring 140.

Similar to the implementation described previously with regard to thedevice 100 of FIGS. 2A-B, the ingress-protected housing of thecontroller 420 of the device 400 protects the components thereunder fromexternal environmental impact, for example damage associated with wateringress. Preventing such ingress protects the electronic components ofthe device 100 from short-circuiting or corrosion of moisture-sensitiveelectronics, for example, when a patient wears the device whileshowering. Such features may also protect from other liquid and solidparticle ingress. In implementations, the ingress-protected housing ofthe controller 420 includes at least one ingress-protected connectorport 421 configured to receive at least one connector 441 of theconductive wiring 440. The at least one ingress-protected connector portcan have an IP67 rating such that the device can be connected to thecontroller 420 and operable when a patient is showering or bathing, forexample.

Additionally, the sash 410 can be water vapor-permeable, andsubstantially liquid-impermeable or waterproof. In implementations, aportion of the sash 410 comprises a water resistant and/or waterprooffabric covering and/or encapsulating electronic components including,for example, the at least one pair of ECG sensing electrodes 412, the atleast one pair of treatment electrodes 414, and the conductive wiring440, and a portion of the sash 410 comprises a water permeable,breathable fabric having a relatively higher moisture vapor transmissionrate that the water resistant and/or waterproof portions. The sash 410can comprise or consist of at least one of neoprene, spandex,nylon-spandex, nylon-LYCRA, ROICA, LINEL, INVIYA, ELASPAN, ACEPORA, andESPA. In examples, the sash 410 can comprise or consist of a fabrichaving a biocompatible surface treatment rendering the fabric waterresistant and/or waterproof. For example, the fabric can be enhanced bydipping in a bath of fluorocarbon, such as Teflon or fluorinated-decylpolyhedral oligomeric silsesquioxane (F-POSS). Additionally oralternatively, the sash 410 can comprise or consist of a fabricincluding anti-bacterial and/or anti-microbial yarns. For example, theseyarns can include a base material of at least one of nylon,polytetrafluoroethylene, and polyester. These yarns can be for example,one or more of an antibacterial silver coated yarn, antibacterialDRAYLON yarn, DRYTEX ANTIBACTERIAL yarn, NILIT BREEZE and NILITBODYFRESH. In implementations, the outer surface of the sash 410 cancomprise one or more patches of an electrostatically dissipativematerial such as a conductor-filled or conductive plastic in order toprevent static cling of a patient's clothing. Alternatively, inembodiments, the sash 410 comprises a static dissipative coating such asLICRON CRYSTAL ESD Safe Coating (TECHSPRAY, Kennesaw, Ga.), a clearelectrostatic dissipative urethane coating.

In implementations, the sash 410 can include one or more sensor ports415 a-c (collectively referred to as 415) for receiving one or morephysiological sensors 423 separate from the at least one pair of ECGsensing electrodes 412. The one or more physiological sensors 423 canbe, for example, sensors for detecting one or more of pulmonaryvibrations (e.g., using microphones and/or accelerometers), breathvibrations, sleep related parameters (e.g., snoring, sleep apnea), andtissue fluids (e.g., using radio-frequency transmitters and sensors).The one or more additional sensors can be, for example, one or morephysiological sensors including a pressure sensor for sensingcompression forces of the garment, SpO2 sensors, blood pressure sensors,bioimpedence sensors, humidity sensors, temperature sensors, andphotoplethysmography sensors. In some examples, the one or more sensorports 415 can also be configured to receive one or more motion and/orposition sensors. For example, such motion sensors can includeaccelerometers for monitoring the movement of the patient's torso in x-,y- and z-axes to determine a movement of the patient, gait, and/orwhether the patient is upright, standing, sitting, lying down, and/orelevated in bed with pillows. In certain implementations, one or moregyroscopes may also be provided to monitor an orientation of thepatient's torso in space to provide information on, e.g., whether thepatient is lying face down or face up, or a direction in which thepatient is facing.

Returning to FIG. 14, the sash 410 can be sized to fit about thethoracic region 105 of the patient. In implementations, the sash 410 canhave proportions and dimensions derived from patient-specific thoracic3D scan dimensions so as to be conformally fitted and shaped to fit theparticular patient's exact body shape, thereby providing a much higherdegree of comfort than an off-the-shelf garment. In implementations,sizing the device to fit the patient comprises determining dimensions ofthe thoracic region 105 in an initial fitting. In implementations, thesash is 3D printed to at least one of body proportions, body shape, bodyposture, and linear surface measurements of the thoracic region of thepatient. In implementations, at least a portion of the sash is 3Dprinted to conform proportions, dimensions, and shape of the sash to oneor more portions and dimensions of the thoracic region 105 and therebyprovides a customize, comfort fit to the patient, further encouragingpatient compliance with wearing the device 400 throughout the prescribedduration of wear.

In implementations, for example, various body size measurements and/or3D images may be obtained from the patient, and one or more portions ofthe sash 410 can be formed of a plastic or polymer to have contoursaccommodating one or more portions of the thoracic region in a fit thatconforms to the specific patient's body shape. A 3D scan can determine,for example, thoracic circumference, lateral width of a patient's chest,contours of the thoracic region, and other relevant physical features ofthe patient. In implementations, one or more portions of the band may be3D printed from, for example, any suitable thermoplastic (e.g., ABSplastic) or any elastomeric and/or flexible 3D printable material. Inimplementations a portion of the sash 410 can be 3D printed to nest withthe contours of the patient's shoulder in a comfort fit, like aprosthetic cup sized and shaped to accommodate a limb. The 3D printedshoulder portion remains seated comfortably on the patient's shoulderand assists with preventing the sash 410 from shifting or rotating. Inimplementations, the sash 410 may include at least two curved rigid orsemi-rigid portions for engaging the patient's shoulder and side, underthe opposite shoulder. The at least two curved portions add rigidstructure that assists with preventing the sash 410 from shifting orrotating about the thoracic region. This stability provides consistencyof sensor signal readings and prevents noise associated with sensormovement.

As described previously, during an initial fitting, a physician,caregiver, or PSR can perform a 3D scan of the patient's thoracic regionusing, for example, three-dimensional imaging systems such as camerasand scanners. For example, imaging system can include a handheld device,such as a handheld digital camera or smart phone, carried by thephysician, caregiver, or PSR.

In implementations, a 3D imaging system can include a plurality ofconventional digital cameras. Although designs differ from differentvendors, as is known in the art, a camera usually comprises acharge-coupled device (CCD) or complementary metal-oxide-semiconductor(CMOS) imaging sensor, a lens, a multifunctional video control chip, anda set of discrete components (e.g., capacitor, resistors, andconnectors). An image is recorded by the imaging sensor and can beprocessed by the video control chip. Captured images can also beprocessed by, for example, a three-dimensional information and/or imageprocessing module configured to identify anatomical structures,distances, and physical objects contained in the captured images.

In some examples, a camera can include one or more of a digital camera,RGB camera, digital video camera, red-green-blue sensor, and/or depthsensor for capturing visual information and static or video images ofthe patient. The camera can also comprise multiple image capturefeatures for obtaining stereo images of the thoracic region 105 of thepatient. The stereo-image can be processed to determine depthinformation for physical features of the patient's thoracic region 105.

In other examples, the camera can be a wide angle or fish-eye camera, athree-dimensional camera, a light-field camera, or similar devices forobtaining images. A light-field or three-dimensional camera can refer toan image capture device having an extended depth of field.Advantageously, the extended depth of field means that during imageprocessing, a user can change focus, point of view, or the perceiveddepth of field of a captured image after the image has been recorded. Assuch, it has been suggested that an image captured using a light-fieldor three-dimensional camera contains all information needed to calculatea three-dimensional form of a patient's thoracic region 105. SeeChristian Perwass, et al. “Single Lens 3D-Camera with ExtendedDepth-of-Field”, Raytrix GmbH, Schauenburgerstr. 116, 24116 Kiel,Germany (2012), which describes an implementation of a light-field 3Dcamera that may be implemented in embodiments of the present disclosure.

In implementations, 3D information and/or images from athree-dimensional imaging system or sensor can be processed to produce athree-dimensional representation of the thoracic region 105. In someembodiments, the 3D imaging system can be configured to project a gridof markers so as to capture high resolution patient anatomical features.For example, a camera using technology similar to that of the Kinectmotion sensing input device provided by Microsoft Corporation may beemployed. Such cameras may include a depth sensor employing an infraredlaser projector combined with a monochrome CMOS sensor which allows for3D video data to be captured under ambient light conditions. It can beappreciated that any suitable 3D imaging systems may be used. A 3Drepresentation may be generated by a 3D surface imaging technology withanatomical integrity, for instance the 3d1VDthorax System (3dMD LLC,Atlanta Ga.).

In implementations, a three-dimensional imaging system may be mounted ona tripod facing the patient or handheld by the caregiver such as usingan iPhoneX provided by Apple Corporation, which has a built-inthree-dimensional imaging system. In implementations, a 3D imagingsystem can comprise one or more of a digital camera, RGB camera, digitalvideo camera, red-green-blue sensor, and/or depth sensor for capturingvisual information and static or video images of the thoracic region105. In some examples, a 3D imaging system can comprise both optical anddepth sensing components as with the Kinect motion sensing input deviceby Microsoft, or the Apple TrueDepth 3D sensing system which may includean infrared camera, flood illuminator, proximity sensor, ambient lightsensor, speaker, microphone, 7-megapixel traditional camera, and dotprojector (which projects up to 30,000 points on an object during ascan).

The patient-specific thoracic 3D scan dimensions can be input intocustom-tailoring software such as ACCUMARK MADE-TO-MEASURE and ACCUMARK3D by Gerber Technology of Tolland, CT, or EFI Optitex 2D and 3Dintegrated pattern design software by EFI Optitex of New York, N.Y. Thedimensions as well as three-dimensional surfaces can also be input intoa 3D printer such as the FORMLABS FORM 3L 3D printer (by Formlabs ofSomerville, MA) using the FORMLABS elastic resin to generate strap orother support elements that conform to the patient's body shape. Theelastic resin comprises a shore durometer of between about 40 A-80 A(e.g. 40 A, 45 A, 50 A, 55 A, 60 A, 65 A, 70 A, 75 A, 80 A).

In addition or alternative to 3D-printing the sash 410 for a custom,nested fit with the morphology of the patient, the sash 410 can alsoprovide a compression fit. In implementations, the sash 410 isconfigured to exert one or more compression forces against the thoracicregion. In implementations, the sash 410 is configured to exert the oneor more compression forces in a range from 0.025 to 0.75 psi to thethoracic region 105. For example, the one or more compression forces canbe in a range from 0.05 psi to 0.70 psi, 0.075 psi to 0.675 psi., or 0.1to 0.65 psi. Compression forces of the medical device can be determined,for example, using one or more pressure sensors and systems as describedabove with regard to the band 110 of FIG. 2A. Immobilizing the sash 410relative to the skin surface reduces or eliminates sensor signal noiseand provides more reliable sensor signals for the processor to analyzethe condition of the patient. In implementations, the sash comprises anunbroken loop comprising a stretchable fabric. The sash 410 can beconfigured to stretch over the shoulders or hips of the patient andcontract when positioned about the thoracic region 105. Inimplementations, the stretchable fabric comprises at least one of nylon,LYCRA, spandex, and neoprene. During an initial fitting, the physician,caregiver, or PSR can select a sash 410 sized to fit the patient. Forexample, the physician, caregiver, or PSR can measure a circumferenceabout one or more locations on the thoracic region 105. The physician,caregiver, or PSR can select a sash 410 having a circumference withinabout 75% to about 95% of the measurement of the one or more locationsabout the thoracic region 105.

In implementations, the sash 410 exerts compression forces against theskin of the patient by one or more of manufacturing all or a portion ofthe sash 410 from a compression fabric, providing one or more tensioningmechanisms in and/or on the sash 410, and proving a cinching closuremechanism for securing and compressing the sash 410 about the thoracicregion 105. In some implementations, the sash 410 comprises anelasticized thread disposed in the sash 410. In some implementations,the sash 410 comprises an elasticized panel spanning less than a totallength of the sash 410. For example, the sash 410 can include one ormore mechanically joined sections forming a continuous length orunbroken loop. The one of the one or more sections can comprise astretchable fabric and/or elasticized thread interspersed withnon-stretchable or relatively less stretchable portions. In otherembodiments, the sash 410 can include an adjustable tension element,such as one or more cables disposed in the sash 410 and configured to betensioned and held in tension by one or more pull stops. In allembodiments, the sash 410 can include one or more visible or mechanicaltension indicators configured to provide a notification of the sash 410exerting compression forces against the thoracic region 105 in a rangefrom about 0.025 psi to 0.75 psi. For example, the tension indicatorscan be configured to provide a notification that the compression forcesare in a range from 0.05 psi to 0.70 psi, about 0.075 psi to 0.675 psi.,or 0.1 psi to 0.65 psi. Compression forces of the medical device can bedetermined, for example, using one or more pressure sensors and systemsas described above with regard to the band 110 of FIG. 2A.

Because the device 400 can be a sash 410 configured to be worn about thethoracic region 105 of the patient, the sash 410 is immobilized bycompression forces and unlikely to shift as the patient moves and goesabout a daily routine. The sash 410 is immobilized relative to the skinsurface of the thoracic region 105 and prevents or eliminates signalnoise associated with sensors shifting against the skin. The size andposition of the sash 410 also provides a discreet and comfortable device400 covering only a relatively small portion of the surface area of theentire thoracic region 105 and accommodating a plurality of body types.In implementations, the band comprises a breathable, skin-facing layerincluding at least one of a compression padding, a silicone tread, andone or more textured surface contours. The breathable material andcompression padding enable patient comfort throughout the duration ofwear and the silicon tread and/or one or more surface contours assistwith immobilizing the sash 410 relative to the skin surface of thethoracic region 105.

Implementations of the device 400 in accordance with the presentdisclosure may exhibit a moisture vapor transmission rate (MVTR) of, forexample, between about 600 g/m2/day and about 1,400 g/m2/day when wornby a subject in an environment at room temperature (e.g., about 25° C.)and at a relative humidity of, for example, about 70%. Inimplementations, the device 100 has a water vapor permeability of 100g/m²/24 hours, as measured by such vapor transmission standards of ASTME-96-80 (Version E96/E96M-13), using either the “in contact with watervapor” (“dry”) or “in contact with liquid” (“wet”) methods. Such testmethods are described in in U.S. Pat. No. 9,867,976, titled “LONG-TERMWEAR ELECTRODE,” issued on Jan. 16, 2018 (hereinafter the “'976Patent”), the disclosure of which is incorporated by reference herein inits entirety. In implementations, the sash 410 comprises one or moremoisture wicking fabrics for assisting with moving moisture away fromthe skin of the thoracic region 105 and improving patient comfortthroughout the prescribed duration of wear.

Similar to implementations of the device of FIGS. 2A-2B, implementationsof the device 400 can optionally include an adhesive configured tosecure the sash 410 to the thoracic region 105 of the patient such thatthe sash 410 is immobile relative to a skin surface of the thoracicregion 105. In implementations, the adhesive is removable and/orreplaceable and has a low skin irritation grading (e.g., a grading of 1)in accordance with the method set forth in American National StandardANSI/AAMI/ISO 10993-10:2010, previously described. For example, theadhesive can comprise one or more adhesive patches 424 configured to bedisposed between the sash 410 and the skin of the patient. The adhesivepatches 424 comprise as pressure-sensitive adhesive having tack,adhesion, and cohesion properties suitable for use with a medical deviceapplied to skin for short term and long-term durations. These pressuresensitive adhesives can include polymers such as acrylics, rubbers,silicones, and polyurethanes having a high initial tack for adhering toskin. These pressure sensitive adhesives also maintain adhesion duringshowering or while a patient is perspiring. The adhesives also enableremoval without leaving behind uncomfortable residue. For example, suchan adhesive can be a rubber blended with a tackifier.

In implementations, the adhesive comprises one or more water vaporpermeable adhesive patches. Additionally or alternatively, the adhesivecan be a conductive patch disposed between the plurality of electrodesand the skin of thoracic region 105, in some implementations. Forexample, as described in the '976 Patent, a water-vapor permeableconductive adhesive patch can be, for example, the flexible, watervapor-permeable, conductive adhesive material can comprise a materialselected from the group consisting of an electro-spun polyurethaneadhesive, a polymerized microemulsion pressure sensitive adhesive, anorganic conductive polymer, an organic semi-conductive conductivepolymer, an organic conductive compound and a semi-conductive conductivecompound, and combinations thereof. In an example, a thickness of theflexible, water vapor-permeable, conductive adhesive material can bebetween 0.25 and 100 mils. In another example, the watervapor-permeable, conductive adhesive material can comprise conductiveparticles. In implementations, the conductive particles may bemicroscopic or nano-scale particles or fibers of materials, includingbut not limited to, one or more of carbon black, silver, nickel,graphene, graphite, carbon nanotubes, and/or other conductivebiocompatible metals such as aluminum, copper, gold, and/or platinum.

In implementations in addition to or alternative to an adhesive, thesash 410 can include an auxiliary strap 445, shown in dashed line inFIG. 14 to indicate optional use. In implementations, a patientoptionally may attach the auxiliary strap 445 around the thoracicregion. In implementations, the auxiliary strap 445 can attach to ananterior portion of the sash 410 with a connector 447 a such as a hookand look fastener, a clip, buttons, or snaps. Similarly, the auxiliarystrap 445 can attach to a posterior portion of the sash 410 with aconnector 447 b such as a hook and look fastener, a clip, buttons, orsnaps. The optionally worn auxiliary strap 445 is configured to preventthe sash 410 from shifting and/or rotating. A patient may attach theauxiliary strap 445 during periods of high activity, such as duringexercise, and remove the auxiliary strap while seated or prone, such aswhile sleeping.

As described above, the teachings of the present disclosure can begenerally applied to external medical monitoring and/or treatmentdevices (e.g., devices that are not completely implanted within thepatient's body). External medical devices can include, for example,ambulatory medical devices that are capable of and designed for movingwith the patient as the patient goes about his or her daily routine. Anexample ambulatory medical device can be a wearable medical device suchas a wearable cardioverter defibrillator (WCD), a wearable cardiacmonitoring device, an in-hospital device such as an in-hospital wearabledefibrillator, a short-term wearable cardiac monitoring and/ortherapeutic device, and other similar wearable medical devices.

A wearable medical cardiac monitoring device is capable of continuoususe by the patient. Further, the wearable medical device can beconfigured as a long-term or extended use medical device. Such devicescan be designed to be used by the patient for a long period of time, forexample, a period of 24 hours or more, several days, weeks, months, oreven years. Accordingly, the long period of use can be uninterrupteduntil a physician or other caregiver provides specific prescription tothe patient to stop use of the wearable medical device. For example, thewearable medical device can be prescribed for use by a patient for aperiod of at least one week. In an example, the wearable medical devicecan be prescribed for use by a patient for a period of at least 30 days.In an example, the wearable medical device can be prescribed for use bya patient for a period of at least one month. In an example, thewearable medical device can be prescribed for use by a patient for aperiod of at least two months. In an example, the wearable medicaldevice can be prescribed for use by a patient for a period of at leastthree months. In an example, the wearable medical device can beprescribed for use by a patient for a period of at least six months. Inan example, the wearable medical device can be prescribed for use by apatient for a long period of at least one year. In some implementations,the extended use can be uninterrupted until a physician or othercaregiver provides specific instruction to the patient to stop use ofthe wearable medical device.

Regardless of the period of wear, the use of the wearable medical devicecan include continuous or nearly continuous wear by the patient aspreviously described. For example, the continuous use can includecontinuous wear of the wearable medical device to the patient.Continuous use can include continuously monitoring the patient while thepatient is wearing the device for cardiac-related information (e.g.,electrocardiogram (ECG) information, including arrhythmia information,cardiac vibrations, etc.) and/or non-cardiac information (e.g., bloodoxygen, the patient's temperature, glucose levels, tissue fluid levels,and/or pulmonary vibrations). For example, the wearable medical devicecan carry out its continuous monitoring and/or recording in periodic oraperiodic time intervals or times (e.g., every few minutes, hours, oncea day, once a week, or other interval set by a technician or prescribedby a caregiver). Alternatively or additionally, the monitoring and/orrecording during intervals or times can be triggered by a user action oranother event.

As noted above, the wearable medical device can be configured to monitorother physiologic parameters of the patient in addition to cardiacrelated parameters. For example, the wearable medical device can beconfigured to monitor, for example, pulmonary-vibrations (e.g., usingmicrophones and/or accelerometers), breath vibrations, sleep relatedparameters (e.g., snoring, sleep apnea), tissue fluids (e.g., usingradio-frequency transmitters and sensors), among others.

In implementations, such as that of FIG. 7, the patient-worn arrhythmiamonitoring and treatment device 100 further includes a patientnotification output via an output device 1216. In response to detectingone or more treatable arrhythmia conditions, the processor 218 isconfigured to prompt the patient for a response by issuing the patientnotification output, which may be an audible output, tactile output,visual output, or some combination of any and all of these types ofnotification outputs. In the absence of a response to the notificationoutput from the patient, the processor is configured to cause thetherapy delivery circuit 1130 to deliver the one or more therapeuticpulses to the patient.

FIG. 15 depicts an example of a process 1500 for determining whether toinitiate a therapy sequence and apply a therapeutic pulse to thethoracic region 105 of a patient. In implementations, the processor 218,receives S1502 a patient ECG signal from the ECG sensing electrodes 212and analyzes S1504 the ECG signal for an arrhythmia condition. Theprocessor 218 determines S1506 whether the arrhythmia is lifethreatening condition and requires treatment. If the arrhythmia is notlife threatening, the processor 218 can cause a portion of the ECGsignal to be stored in memory for later analysis and continue to monitorthe patient ECG signal. If the arrhythmia is life threatening, theprocessor 218 provides S1508 a patient notification output and requestsS1510 a patient response to the provided notification output. Inimplementations, the patient responds to an alert by interacting with auser interface (e.g., the user interface 1208 of FIG. 7), whichincludes, for example, one or more buttons (e.g. the at least one button122, 422 of the device 100, 400, as shown in FIGS. 2A and 14) or touchscreen interface buttons with haptic feedback (e.g., touch screenbuttons on the user interface 1208 of the controller 220, 420 and/or asecond at least one response button of a wearable article (e.g. an armband or wrist worn article comprising at least one of amechanically-actuatable button, a touch screen interface, and at leastone touch screen button on a user interface of the wearable article) orlike devices, such as smartphones running user-facing interactiveapplications). The response may be, for example, pressing one or morebuttons in a particular sequence or for a particular duration. Theprocessor 218 determines S1512 whether the patient response wasreceived. If the patient responds to the notification output, theprocessor 218 is notified that the patient is conscious and returns to amonitoring mode, thereby delaying delivery of a therapeuticdefibrillation or pacing shock. If the patient is unconscious and unableto respond to the provided alert, the processor 218 initiates S1514 thetherapy sequence and treats S1516 the patient with the delivery ofenergy to the thoracic region of the patient. In implementations, if auser response button is pressed for longer than a threshold duration(e.g. longer than 5 seconds), the processor 218 instructs the device toprompt the patient to release the button. If the user response button isnot released the device will return to a state of imminent therapydelivery and will alert the patient to the imminent shock.

FIGS. 2A-6 and 9A-14 illustrate example cardiac monitoring and treatmentdevices that are external, ambulatory, and wearable by a patient, andconfigured to implement one or more configurations described herein. Inexamples, the medical device can include physiological sensorsconfigured to detect one or more cardiac signals. Examples of suchsignals include ECG signals and/or other sensed cardiac physiologicalsignals from the patient. In certain implementations, the physiologicalsensors can include additional components such as accelerometers,vibrational sensors, and other measuring devices for recordingadditional parameters. For example, the physiological sensors can alsobe configured to detect other types of patient physiological parametersand vibrational signals, such as tissue fluid levels, cardio-vibrations,pulmonary-vibrations, respiration-related vibrations of anatomicalfeatures in the airway path, patient movement, etc. Examplephysiological sensors can include ECG sensors including a metalelectrode with an oxide coating such as tantalum pentoxide electrodes,as described in, for example, U.S. Pat. No. 6,253,099 entitled “CardiacMonitoring Electrode Apparatus and Method,” the content of which isincorporated herein by reference.

In examples, the physiological sensors can include a heart rate sensorfor detecting heart beats and monitoring the heart rate of the patient.For instance, such heart rate sensors can include the ECG sensors andassociated circuitry described above. In some examples, the heart ratesensors can include a radio frequency based pulse detection sensor or apulse oximetry sensor worn adjacent an artery of the patient. Inimplementations, the heart rate sensor can be worn about the wrist of apatient, for example, incorporated on and/or within a watch or abracelet. In some examples, the heart rate sensor can be integratedwithin a patch adhesively coupled to the skin of the patient over anartery.

In some examples, the treatment electrodes 114, 214, 414 can also beconfigured to include sensors configured to detect ECG signals as wellas other physiological signals of the patient. The ECG data acquisitionand conditioning circuitry is configured to amplify, filter, anddigitize these cardiac signals. One or more of the treatment electrodes114, 214, 414 can be configured to deliver one or more therapeuticdefibrillating shocks to the body of the patient when the medical devicedetermines that such treatment is warranted based on the signalsdetected by the ECG sensing electrodes 112, 212, 412 and processed bythe processor 218. Example treatment electrodes 114, 214, 414 caninclude conductive metal electrodes such as stainless steel electrodesthat include, in certain implementations, one or more conductive geldeployment devices configured to deliver conductive gel to the metalelectrode prior to delivery of a therapeutic shock.

In some implementations, medical devices as described herein can beconfigured to switch between a therapeutic medical device and amonitoring medical device that is configured to only monitor a patient(e.g., not provide or perform any therapeutic functions). Thetherapeutic elements can be deactivated (e.g., by means or a physical ora software switch), essentially rendering the therapeutic medical deviceas a monitoring medical device for a specific physiologic purpose or aparticular patient. As an example of a software switch, an authorizedperson can access a protected user interface of the medical device andselect a preconfigured option or perform some other user action via theuser interface to deactivate the therapeutic elements of the medicaldevice.

FIG. 7 illustrates an example component-level view of the controller220. As shown in FIG. 7, the controller 220 can include a therapydelivery circuit 1130 including a polarity switching component such asan H-bridge 1228, a data storage 1204 1207, a network interface 1206, auser interface 1208 at least one battery 1140, a sensor interface 1212that includes, for example, an ECG data acquisition and conditioningcircuit, an alarm manager 1214, least one processor 218, and one or morecapacitors 1135. A patient monitoring medical device can includecomponents like those described with regard to FIG. 7, but does notinclude the therapy delivery circuit 1130. Alternatively, a patientmonitoring medical device can include components like those describedwith regard to FIG. 7, but includes a switching mechanism for renderingthe therapy delivery circuit 1130 inoperative. For example, theprocessor 218 can prompt the switching mechanism to render the therapydelivery circuit 1130 inoperative when the second wearable portion 215is not connected to the controller 220.

The therapy delivery circuit 1130 is coupled to two or more treatmentelectrodes configured to provide therapy to the patient. For example,the therapy delivery circuit 1130 includes, or is operably connected to,circuitry components that are configured to generate and provide thetherapeutic shock. The circuitry components include, for example,resistors, one or more capacitors, relays and/or switches, an electricalbridge such as an H-bridge 1228 (e.g., an H-bridge including a pluralityof insulated gate bipolar transistors or IGBTs that deliver and truncatea therapy pulse), voltage and/or current measuring components, and othersimilar circuitry arranged and connected such that the circuitry work inconcert with the therapy delivery circuit and under control of one ormore processors (e.g., processor 218) to provide, for example, one ormore pacing or defibrillation therapeutic pulses.

Pacing pulses can be used to treat cardiac arrhythmias such asbradycardia (e.g., in some implementations, less than 30 beats perminute) and tachycardia (e.g., in some implementations, more than 150beats per minute) using, for example, fixed rate pacing, demand pacing,anti-tachycardia pacing, and the like. Defibrillation pulses can be usedto treat ventricular tachycardia and/or ventricular fibrillation.

In implementations, each of the treatment electrodes 114, 214, 414 has aconductive surface adapted for placement adjacent the patient's skin andhas an impedance reducing means contained therein or thereon forreducing the impedance between a treatment electrode and the patient'sskin. In implementations, each of the treatment electrodes can include aconductive impedance reducing adhesive layer, such as a breathableanisotropic conductive hydrogel disposed between the treatmentelectrodes and the torso of the patient. In implementations, apatient-worn cardiac monitoring and treatment device may include geldeployment circuitry configured to cause the delivery of conductive gelsubstantially proximate to a treatment site (e.g., a surface of thepatient's skin in contact with the treatment electrode 114) prior todelivering therapeutic shocks to the treatment site. As described inU.S. Pat. No. 9,008,801, titled “WEARABLE THERAPUETIC DEVICE,” issued onApr. 14, 2015 (hereinafter the “'801 Patent”), which is incorporatedherein by reference in its entirety, the gel deployment circuitry can beconfigured to cause the delivery of conductive gel immediately beforedelivery of the therapeutic shocks to the treatment site, or within ashort time interval, for example, within about 1 second, 5 seconds, 10seconds, 30 seconds, or one minute before delivery of the therapeuticshocks to the treatment site. Such gel deployment circuitry can becoupled to or integrated with each of the treatment electrodes 114, 214,414.

When a treatable cardiac condition is detected and no patient responseis received after device prompting, the gel deployment circuitry can besignaled to deploy the conductive gel. In some examples, the geldeployment circuitry can be constructed as one or more separate andindependent gel deployment modules. Such modules can be configured toreceive removable and/or replaceable gel cartridges (e.g., cartridgesthat contain one or more conductive gel reservoirs). As such, the geldeployment circuitry can be permanently disposed in the device as partof the therapy delivery systems, while the cartridges can be removableand/or replaceable.

In some implementations, the gel deployment modules can be implementedas gel deployment packs and include at least a portion of the geldeployment circuitry along with one or more gel reservoirs within thegel deployment pack. In such implementations, the gel deployment pack,including the one or more gel reservoirs and associated gel deploymentcircuitry can be removable and/or replaceable. In some examples, the geldeployment pack, including the one or more gel reservoirs and associatedgel deployment circuitry, and the treatment electrode can be integratedinto a treatment electrode assembly that can be removed and replaced asa single unit either after use, or if damaged or broken.

Continuing with the description of the example medical device of FIG. 7,in implementations, the one or more capacitors 1135 is a plurality ofcapacitors (e.g., two, three, four or more capacitors) comprising acapacitor bank 1402. These capacitors 1135 can be switched into a seriesconnection during discharge for a defibrillation pulse. For example,four capacitors of approximately 650 μF can be used. In oneimplementation, the capacitors can have between 200 to 2500 volt surgerating and can be charged in approximately 5 to 30 seconds from abattery 1140 depending on the amount of energy to be delivered to thepatient.

For example, each defibrillation pulse can deliver between 60 to 400joules (J) of energy. In some implementations, the defibrillating pulsecan be a biphasic truncated exponential waveform, whereby the signal canswitch between a positive and a negative portion (e.g., chargedirections). An amplitude and a width of the two phases of the energywaveform can be automatically adjusted to deliver a predetermined energyamount.

The data storage 1207 can include one or more of non-transitory computerreadable media, such as flash memory, solid state memory, magneticmemory, optical memory, cache memory, combinations thereof, and others.The data storage 1207 can be configured to store executable instructionsand data used for operation of the medical device. In certainimplementations, the data storage 1207 can include executableinstructions that, when executed, are configured to cause the processor218 to perform one or more functions.

In some examples, the network interface 1206 can facilitate thecommunication of information between the medical device and one or moreother devices or entities over a communications network. For example,the network interface 1206 can be configured to communicate with aremote computing device such as a remote server or other similarcomputing device. The network interface 1206 can include communicationscircuitry for transmitting data in accordance with a BLUETOOTH wirelessstandard for exchanging such data over short distances to anintermediary device(s) (e.g., a base station, a “hotspot” device, asmartphone, a tablet, a portable computing device, and/or other devicesin proximity of the wearable medical device 100). The intermediarydevice(s) may in turn communicate the data to a remote server over abroadband cellular network communications link. The communications linkmay implement broadband cellular technology (e.g., 2.5G, 2.75G, 3G, 4G,5G cellular standards) and/or Long-Term Evolution (LTE) technology orGSM/EDGE and UMTS/HSPA technologies for high-speed wirelesscommunication. In some implementations, the intermediary device(s) maycommunicate with a remote server over a WI-FI communications link basedon the IEEE 802.11 standard.

In certain implementations, the user interface 1208 can include one ormore physical interface devices such as input devices, output devices,and combination input/output devices and a software stack configured todrive operation of the devices. These user interface elements may rendervisual, audio, and/or tactile content. Thus, the user interface 1208 mayreceive input or provide output, thereby enabling a user to interactwith the medical device. In some implementations, the user interface1208 can be implemented as a wearable article or as a hand-held userinterface device (for example, wearable articles including the patientinterface pod 40 of FIG. 1 and the wrist and arm worn remote devices.)For instance, a hand-held user interface device can be a smartphone orother portable device configured to communicate with the processor 218via the network interface 1206. In an implementation, the hand-held userinterface device may also be the intermediary device for facilitatingthe transfer of information from the device to a remote server.

As described, the medical device can also include at least one battery1140 configured to provide power to one or more components, such as theone or more capacitors 1135. The battery 1140 can include a rechargeablemulti-cell battery pack. In one example implementation, the battery 1140can include three or more 2200 mAh lithium ion cells that provideelectrical power to the other device components. For example, thebattery 1140 can provide its power output in a range of between 20 mA to1000 mA (e.g., 40 mA) output and can support 24 hours, 48 hours, 72hours, or more, of runtime between charges. As previously descried indetail, in certain implementations, the battery capacity, runtime, andtype (e.g., lithium ion, nickel-cadmium, or nickel-metal hydride) can bechanged to best fit the specific application of the medical device.

The sensor interface 1202 can be coupled to one or more sensorsconfigured to monitor one or more physiological parameters of thepatient. As shown in FIG. 7 the sensors can be coupled to the medicaldevice controller (e.g., processor 218) via a wired or wirelessconnection. The sensors can include one or more sensing electrodes(e.g., ECG sensing electrode 212), vibrations sensors 1224, and tissuefluid monitors 1226 (e.g., based on ultra-wide band radiofrequencydevices). For example, the sensor interface 1202 can include ECGcircuitry (such as ECG acquisition and conditioning circuitry) and/oraccelerometer circuitry, which are each configured to receive andcondition the respective sensor signals.

The sensing electrodes can monitor, for example, a patient's ECGinformation. For example, the sensing electrodes of FIG. 7 can be ECGsensing electrodes 212 and can include conductive electrodes with storedgel deployment (e.g., metallic electrodes with stored conductive gelconfigured to be dispersed in the electrode-skin interface when needed),conductive electrodes with a conductive adhesive layer, or dryelectrodes (e.g., a metallic substrate with an oxide layer in directcontact with the patient's skin). The sensing electrodes can beconfigured to measure the patient's ECG signals. The sensing electrodescan transmit information descriptive of the ECG signals to the sensorinterface 1202 for subsequent analysis.

The vibrations sensors 1224 can detect a patient's cardiac or pulmonary(cardiopulmonary) vibration information. For example, thecardiopulmonary vibrations sensors 1224 can be configured to detectcardio-vibrational biomarkers in a cardio-vibrational signal, includingany one or all of S1, S2, S3, and S4 cardio-vibrational biomarkers. Fromthese cardio-vibrational biomarkers, certain electromechanical metricscan be calculated, including any one or more of electromechanicalactivation time (EMAT), percentage of EMAT (% EMAT), systolicdysfunction index (SDI), left ventricular diastolic perfusion time(LDPT), and left ventricular systolic time (LVST). The cardiopulmonaryvibrations sensors 1224 may also be configured to detect heart wallmotion, for example, by placement of the cardiopulmonary vibrationssensor 1224 in the region of the apical beat.

The vibrations sensors 1224 can include an acoustic sensor configured todetect vibrations from a subject's cardiac or pulmonary(cardiopulmonary) system and provide an output signal responsive to thedetected vibrations of the targeted organ. For instance, in someimplementations, the vibrations sensors 1224 are able to detectvibrations generated in the trachea or lungs due to the flow of airduring breathing. The vibrations sensors 1224 can also include amulti-channel accelerometer, for example, a three channel accelerometerconfigured to sense movement in each of three orthogonal axes such thatpatient movement/body position can be detected. The vibrations sensors1224 can transmit information descriptive of the cardiopulmonaryvibrations information or patient position/movement to the sensorinterface 1202 for subsequent analysis.

The tissue fluid monitors 1226 can use radio frequency (RF) basedtechniques to assess changes of accumulated fluid levels over time. Forexample, the tissue fluid monitors 1226 can be configured to measurefluid content in the lungs (e.g., time-varying changes and absolutelevels), for diagnosis and follow-up of pulmonary edema or lungcongestion in heart failure patients. The tissue fluid monitors 1226 caninclude one or more antennas configured to direct RF waves through apatient's tissue and measure output RF signals in response to the wavesthat have passed through the tissue. In certain implementations, theoutput RF signals include parameters indicative of a fluid level in thepatient's tissue. The tissue fluid monitors 1226 can transmitinformation descriptive of the tissue fluid levels to the sensorinterface 1202 for subsequent analysis.

The sensor interface 1202 can be coupled to any one or combination ofsensing electrodes/other sensors to receive other patient dataindicative of patient parameters. Once data from the sensors has beenreceived by the sensor interface 1202, the data can be directed by theprocessor 218 to an appropriate component within the medical device. Forexample, if cardiac data is collected by the cardiopulmonary vibrationssensor 1224 and transmitted to the sensor interface 1202, the sensorinterface 1202 can transmit the data to the processor 218 which, inturn, relays the data to a cardiac event detector. The cardiac eventdata can also be stored on the data storage 1207.

An alarm manager 1214 can be configured to manage alarm profiles andnotify one or more intended recipients of events specified within thealarm profiles as being of interest to the intended recipients. Theseintended recipients can include external entities such as users (e.g.,patients, physicians, other caregivers, patient care representatives,and other authorized monitoring personnel) as well as computer systems(e.g., monitoring systems or emergency response systems). The alarmmanager 1214 can be implemented using hardware or a combination ofhardware and software. For instance, in some examples, the alarm manager1214 can be implemented as a software component that is stored withinthe data storage 1207 and executed by the processor 218. In thisexample, the instructions included in the alarm manager 1214 can causethe processor 218 to configure alarm profiles and notify intendedrecipients according to the configured alarm profiles. In some examples,alarm manager 1214 can be an application-specific integrated circuit(ASIC) that is coupled to the processor 218 and configured to managealarm profiles and notify intended recipients using alarms specifiedwithin the alarm profiles. Thus, examples of alarm manager 1214 are notlimited to a particular hardware or software implementation.

In some implementations, the processor 218 includes one or moreprocessors (or one or more processor cores) that each are configured toperform a series of instructions that result in manipulated data and/orcontrol the operation of the other components of the medical device. Insome implementations, when executing a specific process (e.g., cardiacmonitoring), the processor 218 can be configured to make specificlogic-based determinations based on input data received, and be furtherconfigured to provide one or more outputs that can be used to control orotherwise inform subsequent processing to be carried out by theprocessor 218 and/or other processors or circuitry with which processor218 is communicatively coupled. Thus, the processor 218 reacts to aspecific input stimulus in a specific way and generates a correspondingoutput based on that input stimulus. In some example cases, theprocessor 218 can proceed through a sequence of logical transitions inwhich various internal register states and/or other bit cell statesinternal or external to the processor 218 can be set to logic high orlogic low. The processor 218 can be configured to execute a functionstored in software. For example, such software can be stored in a datastore coupled to the processor 218 and configured to cause the processor218 to proceed through a sequence of various logic decisions that resultin the function being executed. The various components that aredescribed herein as being executable by the processor 218 can beimplemented in various forms of specialized hardware, software, or acombination thereof. For example, the processor can be a digital signalprocessor (DSP) such as a 24-bit DSP processor. The processor 218 can bea multi-core processor, e.g., a processor having two or more processingcores. The processor can be an Advanced RISC Machine (ARM) processorsuch as a 32-bit ARM processor or a 64-bit ARM processor. The processorcan execute an embedded operating system and include services providedby the operating system that can be used for file system manipulation,display & audio generation, basic networking, firewalling, dataencryption and communications.

In implementations, the therapy delivery circuit 1130 includes, or isoperably connected to, circuitry components that are configured togenerate and provide the therapeutic shock. As described previously, thecircuitry components include, for example, resistors, one or morecapacitors 1135, relays and/or switches, an electrical bridge such as anH-bridge 1228 (e.g., an H-bridge circuit including a plurality ofswitches, (e.g. insulated gate bipolar transistors or IGBTs, siliconcarbide field effect transistors (SiC FETs), metal-oxide semiconductorfield effect transistors (MOSFETS), silicon-controlled rectifiers(SCRs), or other high current switching devices)), voltage and/orcurrent measuring components, and other similar circuitry componentsarranged and connected such that the circuitry components work inconcert with the therapy delivery circuit 1130 and under control of oneor more processors (e.g., processor 218) to provide, for example, one ormore pacing or defibrillation therapeutic pulses.

In implementations, the device further includes a source of electricalenergy, for example, the one or more capacitors 1135, that stores andprovides energy to the therapy delivery circuit 1130. The one or moretherapeutic pulses are defibrillation pulses of electrical energy, andthe one or more treatable arrhythmias include ventricular fibrillationand ventricular tachycardia. In implementations, the one or moretherapeutic pulses are biphasic exponential pulses. Such therapeuticpulses can be generated by charging the one or more capacitors 1135 anddischarging the energy stored in the one or more capacitors 1135 intothe patient. For example, the therapy delivery circuit 1130 can includeone or more power converters for controlling the charging anddischarging of the one or more capacitors 1135. In some implementations,the discharge of energy from the one or more capacitors 1135 can becontrolled by, for example, an H-bridge that controls the discharge ofenergy into the body of the patient, like the H-bridge circuit describedin U.S. Pat. No. 6,280,461, titled “PATIENT-WORN ENERGY DELIVERYAPPARATUS,” issued on Aug. 28, 2001, and U.S. Pat. No. 8,909,335, titled“METHOD AND APPARATUS FOR APPLYING A RECTILINEAR BIPHASIC POWER WAVEFORMTO A LOAD,” issued on Dec. 9, 2014, each of which is hereby incorporatedherein by reference in its entirety.

As shown in the embodiment to FIG. 16, the H-bridge 1228 is electricallycoupled to a capacitor bank 1402 including four capacitors 1135 a-d thatare charged in parallel at a preparation phase 1227 a and discharged inseries at a treatment phase 1227 b. In some implementations, thecapacitor bank 1402 can include more or fewer than four capacitors 1135.During the treatment phase 1227 b, the H-bridge 1228 applies atherapeutic pulse that causes current to flow through the torso 5 of apatient 101 in desired directions for desired durations. The H-bridge1228 includes H-bridge switches 1229 a-d that are opened and closedselectively by a switching transistor such as insulated gate bipolartransistors (IGBTs), silicon carbide field effect transistors (SiCFETs), metal-oxide semiconductor field effect transistors (MOSFETS),silicon-controlled rectifiers (SCRs), or other high current switchingdevices. Switching a pair of transistors to a closed position, forexample switches 1229 a and 1229 c, enables current to flow in a firstdirection for first pulse segment P1. Opening switches 1229 a and 1229 cand closing switches 1229 b and 1229 d enables current to flow throughthe torso 5 of the patient 101 in a second pulse segment P2directionally opposite the flow of the first pulse segment P1.

Although the subject matter contained herein has been described indetail for the purpose of illustration, it is to be understood that suchdetail is solely for that purpose and that the present disclosure is notlimited to the disclosed embodiments, but, on the contrary, is intendedto cover modifications and equivalent arrangements that are within thespirit and scope of the appended claims. For example, it is to beunderstood that the present disclosure contemplates that, to the extentpossible, one or more features of any embodiment can be combined withone or more features of any other embodiment.

Other examples are within the scope and spirit of the description andclaims. Additionally, certain functions described above can beimplemented using software, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions can alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

What is claimed is:
 1. An ergonomic and unobtrusive cardiac monitoringand treatment device for continuous wear, comprising a sash configuredto be worn over only a first shoulder of a patient and under only asecond shoulder of the patient, the sash encircling a thoracic region ofthe patient, extending from over the first shoulder of the patientacross an anterior area of the thoracic region to an opposite lateralside of the thoracic region under the second shoulder of the patientadjacent to an axilla and further extending across a posterior area ofthe thoracic region from under the second shoulder to over the firstshoulder; a plurality of electrodes and associated circuitry disposedabout the sash, the plurality of electrodes and associated circuitrycomprising at least one pair of ECG sensing electrodes disposed aboutthe sash, the at least one pair of ECG sensing electrodes configured tosense an ECG signal of the patient, an ECG acquisition circuit incommunication with the at least one pair of ECG sensing electrodes andconfigured to provide ECG information of the patient based on the sensedECG signal, at least one pair of treatment electrodes disposed about thesash and coupled to a treatment delivery circuit and configured todeliver an electrotherapy to the patient, a first one of the at leastone pair of treatment electrodes being configured to be located withinthe anterior area of the thoracic region and a second one of the atleast one pair of treatment electrodes being configured to be locatedwithin the posterior area of the thoracic region of the patient, thetreatment delivery circuit being in communication with the at least onepair of treatment electrodes and configured to cause delivery of theelectrotherapy to the patient, and a connection pod disposed on thesash, the connection pod in wired connection with the at least one pairof ECG sensing electrodes and the at least one pair of treatmentelectrodes, wherein the connection pod comprises the ECG acquisitioncircuit; wherein the sash is configured to immobilize the at least onepair of ECG sensing electrodes relative to a skin surface of thethoracic region by exerting one or more compression forces in a range ofabout 0.025 to 0.75 psi on the thoracic region of the patient; and acontroller in communication with the connection pod and comprising aningress-protected housing, and a processor disposed within theingress-protected housing, the processor configured to analyze the ECGinformation of the patient from the ECG acquisition circuit and detectone or more treatable arrhythmias based on the ECG information, andcause the treatment delivery circuit to deliver the electrotherapy tothe patient on detecting the one or more treatable arrhythmias.
 2. Thedevice of claim 1, wherein the sash is sized to fit the thoracic region.3. The device of claim 2, wherein sized to fit comprises determiningdimensions of the thoracic region in an initial fitting, wherein sashproportions and dimensions are derived from a 3D scan of the thoracicregion such that the sash is sized to fit proportions, dimensions, and ashape of the thoracic region.
 4. The device of claim 3, wherein at leasta portion of the sash is 3D-printed to conform the sash to at least oneof body proportions, body shape, body posture, or linear surfacemeasurements of the thoracic region of the patient.
 5. The device ofclaim 1, wherein the at least one pair of ECG sensing electrodes isconfigured to be affixed to the sash.
 6. The device of claim 1, whereinthe at least one pair of treatment electrodes is configured to beaffixed to the sash.
 7. The device of claim 1, wherein the at least onepair of ECG sensing electrodes comprises fabric ECG sensing electrodesdisposed on the sash.
 8. The device of claim 1, further comprising oneor more sensor ports for receiving one or more physiological sensors. 9.The device of claim 8, wherein the one or more sensor ports areconfigured to receive at least one of a radio-frequency sensor, abioimpedance sensor, or a photoplethysmography sensor.
 10. The device ofclaim 1, further comprising an accelerometer, and wherein the processoris further configured to determine at least one of movement of thepatient or an orientation of the patient.
 11. The device of claim 10,wherein determining the orientation of the patient comprisingdetermining at least one of whether the patient is upright, standing,sitting, lying down, or elevated.
 12. The device of claim 1, wherein theone or more compression forces are in a range from 0.05 to 0.70 psi. 13.The device of claim 1, wherein the one or more compression forces are ina range from 0.075 to 0.675 psi.
 14. The device of claim 1, wherein theone or more compression forces are in a range from 0.1 to 0.65 psi. 15.The device of claim 1, wherein the device is configured to provide anotification of the one or more compression forces exerted by the sash.16. The device of claim 15, further comprising one or more pressuresensors distributed on the sash, wherein the notification of the one ormore compression forces exerted by the sash is based on data from theone or more pressure sensors.
 17. The device of claim 16, wherein theone or more pressure sensors comprise one or more force sensitiveresistors.
 18. The device of claim 1, wherein the sash is configured tohave a moisture vapor transmission rate between about 100 g/m²/day andabout 1,400 g/m²/day.
 19. The device of claim 18, wherein the sash isconfigured to have a moisture vapor transmission rate between about 600g/m²/day and about 1,400 g/m²/day.